What I would like is to be able to export to a named sheet and keep the other sheets in file. For example:
"Sheet 1" (with new values), "Sheet2" (with old values)

Using your current naming convention, the Option might be named FileExportMode.CreateOrOverrideSheet

The group description now has AutoShowSubTotals property determining whether subtotals will be generated for the description:

this.radPivotGrid1.RowGroupDescriptions.Add(new DateTimeGroupDescription
{
    PropertyName = "OrderDate",
    Step = DateTimeStep.Quarter,
    GroupComparer = new GroupNameComparer(),
    AutoShowSubTotals = false
});

Hour, minute, second, if possible also week

The new API would allow some of the default functions to be removed and custom aggregate functions to be added. At the moment the dialog can be modified like this:

Public Class MyAggregateOptionsDialog
    Inherits AggregateOptionsDialog

    Private availableAggregateFunctions As IList(Of AggregateFunction) = New List(Of AggregateFunction)() From {
        AggregateFunctions.Sum,
        AggregateFunctions.Count,
        AggregateFunctions.Average,
        AggregateFunctions.Max,
        AggregateFunctions.Min,
        AggregateFunctions.Product,
        AggregateFunctions.StdDev,
        AggregateFunctions.StdDevP,
        AggregateFunctions.Var,
        AggregateFunctions.VarP,
        New SqrtSumAggregateFunction()
    }

    Public Overrides Sub LoadSettings(aggregateDescription As PropertyAggregateDescriptionBase)
        MyBase.LoadSettings(aggregateDescription)

        Dim listAggregateFunctions = DirectCast(Me.GetType().BaseType.GetField("listAggregateFunctions", BindingFlags.NonPublic Or BindingFlags.Instance).GetValue(Me), RadListControl)
        listAggregateFunctions.DataSource = availableAggregateFunctions
    End Sub
End Class

RadPivotGrid Implement logic when the user clicks on a cell to get the underlying data

Until the feature gets implemented create a custom PivotFieldListVisualItem and translate each of the items individually:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
 
        this.radPivotFieldList1.RowLabelsControl.CreatingVisualListItem += ListControl_CreatingVisualListItem;
        this.radPivotFieldList1.ColumnLabelsControl.CreatingVisualListItem += ListControl_CreatingVisualListItem;
        this.radPivotFieldList1.ReportFiltersControl.CreatingVisualListItem += ListControl_CreatingVisualListItem;
        this.radPivotFieldList1.ValuesControl.CreatingVisualListItem += ListControl_CreatingVisualListItem;
    }
 
    private void ListControl_CreatingVisualListItem(object sender, CreatingVisualListItemEventArgs args)
    {
        args.VisualItem = new MyPivotFieldListVisualItem(this.radPivotFieldList1.ViewModel);
    }
}
 
public class MyPivotFieldListVisualItem : PivotFieldListVisualItem
{
    public MyPivotFieldListVisualItem(FieldListViewModel viewModel)
        : base(viewModel) { }
 
    protected override void CreateChildElements()
    {
        base.CreateChildElements();
 
        CommandBarDropDownButton btn = this.GetType().BaseType
            .GetField("button", BindingFlags.Instance | BindingFlags.NonPublic)
            .GetValue(this) as CommandBarDropDownButton;
 
        if (btn != null)
        {
            btn.DropDownMenu.PopupOpening += DropDownMenu_PopupOpening;
        }
    }
 
    private void DropDownMenu_PopupOpening(object sender, System.ComponentModel.CancelEventArgs args)
    {
        foreach (RadItem item in ((RadDropDownMenu)sender).Items)
        {
            // Validate and localize each of the items
            if (item is RadMenuItem)
            {
                item.Text = "MyText";
            }
        }
    }
}

Until the feature becomes available use the following workaround:

MyPivotGridChartDataProvider chartProvider = new MyPivotGridChartDataProvider(this.radPivotGrid1.PivotGridElement);
this.radPivotGrid1.ChartDataProvider = chartProvider;
this.radChartView1.DataSource = this.radPivotGrid1;
this.radChartView1.ShowLegend = true;
this.radPivotGrid1.ChartDataProvider.SeriesAxis = Telerik.Pivot.Core.PivotAxis.Rows;
this.radPivotGrid1.ChartDataProvider.GeneratedSeriesType = Telerik.WinControls.UI.GeneratedSeriesType.Line;

public class MyPivotGridChartDataProvider : PivotGridChartDataProvider
{
    public MyPivotGridChartDataProvider(RadPivotGridElement pivotGridElement)
        : base(pivotGridElement) { }

    public override void UpdateChartData()
    {
        base.UpdateChartData();

        foreach (ChartSeries series in this.ChartView.Series)
        {
            CartesianSeries cartesianSeries = series as CartesianSeries;
            if (cartesianSeries == null)
            {
                continue;
            }

            cartesianSeries.PointSize = new SizeF(7, 7);

            BindingList<PivotChartModelPoint> newData = new BindingList<PivotChartModelPoint>();
            BindingList<PivotDataPoint> points = cartesianSeries.DataSource as BindingList<PivotDataPoint>;

            foreach (PivotDataPoint point in points)
            {
                PivotChartModelPoint current = new PivotChartModelPoint() { Group = point.PivotGroup };
                if (point.Value != 0)
                {
                    current.Value = point.Value;
                }
                else
                {
                    current.Value = null;
                }

                newData.Add(current);
            }

            cartesianSeries.DataSource = null;

            cartesianSeries.CategoryMember = "Group";
            cartesianSeries.ValueMember = "Value";
            cartesianSeries.DataSource = newData;
        }
    }
}

public class PivotChartModelPoint
{
    public string Group{ get; set; }

    public double? Value { get; set; }
}

Workaround:

public Form1()
{
    InitializeComponent();

    this.radPivotFieldList1.ValuesControl.CreatingVisualListItem += Aggregates_CreatingVisualListItem;
}

private void Aggregates_CreatingVisualListItem(object sender, Telerik.WinControls.UI.CreatingVisualListItemEventArgs args)
{
    args.VisualItem = new MyPivotFieldListVisualItem(this.radPivotFieldList1.ViewModel);
}

    public class MyPivotFieldListVisualItem : PivotFieldListVisualItem
    {
        private FieldListViewModel viewModel;
 
        private CommandBarDropDownButton button;
        private RadMenuItem sumMenuItem;
        private RadMenuItem avgMenuItem;
        private RadMenuItem countMenuItem;
 
        public MyPivotFieldListVisualItem(FieldListViewModel viewModel)
            : base(viewModel)
        {
            this.viewModel = viewModel;
        }
 
        protected override void CreateChildElements()
        {
            base.CreateChildElements();
 
            this.sumMenuItem = this.GetType().BaseType
                .GetField("sumMenuItem", BindingFlags.Instance | BindingFlags.NonPublic)
                .GetValue(this) as RadMenuItem;
 
            this.avgMenuItem = this.GetType().BaseType
              .GetField("avgMenuItem", BindingFlags.Instance | BindingFlags.NonPublic)
              .GetValue(this) as RadMenuItem;
 
            this.countMenuItem = this.GetType().BaseType
              .GetField("countMenuItem", BindingFlags.Instance | BindingFlags.NonPublic)
              .GetValue(this) as RadMenuItem;
 
            if (sumMenuItem != null && avgMenuItem != null && countMenuItem != null)
            {
                sumMenuItem.Click += OnAggregateFunctionClick;
                avgMenuItem.Click += OnAggregateFunctionClick;
                countMenuItem.Click += OnAggregateFunctionClick;
            }
 
            this.button = this.GetType().BaseType
             .GetField("button", BindingFlags.Instance | BindingFlags.NonPublic)
             .GetValue(this) as CommandBarDropDownButton;
 
            RadMenuItem aggregateOptionsMenuItem = this.GetType().BaseType
                .GetField("aggregateOptionsMenuItem", BindingFlags.Instance | BindingFlags.NonPublic)
                .GetValue(this) as RadMenuItem;
 
            aggregateOptionsMenuItem.Click += aggregateOptionsMenuItem_Click;
 
            RadMenuItem numberFormatMenuItem = this.GetType().BaseType
                .GetField("numberFormatMenuItem", BindingFlags.Instance | BindingFlags.NonPublic)
                .GetValue(this) as RadMenuItem;
 
            numberFormatMenuItem.Click += numberFormatMenuItem_Click;
        }
 
        private void numberFormatMenuItem_Click(object sender, EventArgs e)
        {
            Value value = (this.Data.DataBoundItem as Value);
            if (value == null)
            {
                return;
            }
 
            MyNumberFormatOptionsDialog dialog =  new MyNumberFormatOptionsDialog();
            dialog.ThemeName = this.GetThemeName();
 
            QueryableAggregateDescription queryableAggregateDescription = (value.Description as QueryableAggregateDescription);
            if (queryableAggregateDescription != null)
            {
                dialog.LoadQueryableSettings(queryableAggregateDescription);
            }
 
            System.Windows.Forms.DialogResult result = dialog.ShowDialog();
 
            if (result == System.Windows.Forms.DialogResult.OK)
            {
                queryableAggregateDescription.StringFormat = dialog.SelectedStringFormat;
                this.viewModel.ExecuteUpdate();
            }
        }
 
        private void aggregateOptionsMenuItem_Click(object sender, EventArgs e)
        {
            MyAggregateOptionsDialog dialog = new MyAggregateOptionsDialog();
            dialog.ThemeName = this.GetThemeName();
 
            Value value = (this.Data.DataBoundItem as Value);
            if (value != null)
            {
                QueryablePropertyAggregateDescriptionBase queryableAggregateDescription = (value.Description as QueryablePropertyAggregateDescriptionBase);
                if (queryableAggregateDescription != null)
                {
                    dialog.LoadQueryableSettings(queryableAggregateDescription);
                }
 
                System.Windows.Forms.DialogResult result = dialog.ShowDialog();
                if (result == System.Windows.Forms.DialogResult.OK)
                {
                    queryableAggregateDescription.AggregateFunction = dialog.SelectedQueryableAggregateFunction;
                    queryableAggregateDescription.CustomName = dialog.CustomName;
 
                    this.Synchronize();
                    this.viewModel.ExecuteUpdate();
                }
            }
        }
 
        private void OnAggregateFunctionClick(object sender, EventArgs e)
        {
            Value value = (this.Data.DataBoundItem as Value);
            string function = ((RadMenuItem)sender).Text;
 
            if (value != null && this.SetNewAggregateFunction(value.Description, function))
            {
                this.Synchronize();
                this.viewModel.ExecuteUpdate();
            }
        }
 
        private bool SetNewAggregateFunction(IAggregateDescription description, string function)
        {
            QueryablePropertyAggregateDescriptionBase queryableDescription = (description as QueryablePropertyAggregateDescriptionBase);
            if (queryableDescription != null)
            {
                switch (function)
                {
                    case "Sum":
                        queryableDescription.AggregateFunction = QueryableAggregateFunction.Sum;
                        break;
                    case "Count":
                        queryableDescription.AggregateFunction = QueryableAggregateFunction.Count;
                        break;
                    case "Average":
                        queryableDescription.AggregateFunction = QueryableAggregateFunction.Average;
                        break;
                    default:
                        return false;
                }
 
                return true;
            }
 
            return false;
        }
 
        protected override void SynchronizeProperties()
        {
            base.SynchronizeProperties();
 
            Value value = (this.Data.DataBoundItem as Value);
            Label label = (this.Data.DataBoundItem as Label);
 
            if (value != null)
            {
#if !NETFX2
                QueryablePropertyAggregateDescription queryableDescription = (value.Description as QueryablePropertyAggregateDescription);
                if (queryableDescription != null)
                {
                    this.sumMenuItem.IsChecked = queryableDescription.AggregateFunction == QueryableAggregateFunction.Sum;
                    this.countMenuItem.IsChecked = queryableDescription.AggregateFunction == QueryableAggregateFunction.Count;
                    this.avgMenuItem.IsChecked = queryableDescription.AggregateFunction == QueryableAggregateFunction.Average;
                }
#endif
            }
        }
 
        private string GetThemeName()
        {
            if (this.ElementTree == null)
            {
                return string.Empty;
            }
 
            RadControl control = this.ElementTree.Control as RadControl;
 
            return control != null ? control.ThemeName : string.Empty;
        }
    }
 
public class MyAggregateOptionsDialog : AggregateOptionsDialog
    {
        private RadListControl listAggregateFunctions;
        private RadLabel labelFieldName;
        private RadTextBox textBoxCustomName;

        public MyAggregateOptionsDialog()
        {
            this.listAggregateFunctions = this.GetType().BaseType
               .GetField("listAggregateFunctions", BindingFlags.Instance | BindingFlags.NonPublic)
               .GetValue(this) as RadListControl;

            this.labelFieldName = this.GetType().BaseType
                .GetField("labelFieldName", BindingFlags.Instance | BindingFlags.NonPublic)
                .GetValue(this) as RadLabel;

            this.textBoxCustomName = this.GetType().BaseType
                .GetField("textBoxCustomName", BindingFlags.Instance | BindingFlags.NonPublic)
                .GetValue(this) as RadTextBox;
        }

        private readonly IList<QueryableAggregateFunction> availableQueryableAggregateFunctions = new List<QueryableAggregateFunction>()
            {
                QueryableAggregateFunction.Sum,
                QueryableAggregateFunction.Count,
                QueryableAggregateFunction.Average,
                QueryableAggregateFunction.Max,
                QueryableAggregateFunction.Min
            };

        public virtual QueryableAggregateFunction SelectedQueryableAggregateFunction
        {
            get
            {
                return (QueryableAggregateFunction)this.listAggregateFunctions.SelectedValue;
            }
        }

        public virtual void LoadQueryableSettings(QueryablePropertyAggregateDescriptionBase aggregateDescription)
        {
            if (this.listAggregateFunctions.DataSource != null)
            {
                this.listAggregateFunctions.DataSource = availableQueryableAggregateFunctions;
            }

            this.listAggregateFunctions.SelectedValue = aggregateDescription.AggregateFunction;
            this.labelFieldName.Text = aggregateDescription.PropertyName;
            this.Text = String.Format("{0}{1}{2}", "Aggregate Options (", aggregateDescription.PropertyName, ")");
            this.textBoxCustomName.Text = aggregateDescription.CustomName;
        }
    }

public class MyNumberFormatOptionsDialog : NumberFormatOptionsDialog
    {
        private TextBox textBox;

        public MyNumberFormatOptionsDialog()
        {
            RadDropDownList dropDownListFormat = this.GetType().BaseType
                   .GetField("dropDownListFormat", BindingFlags.Instance | BindingFlags.NonPublic)
                   .GetValue(this) as RadDropDownList;

            this.textBox = (TextBox)dropDownListFormat.DropDownListElement.EditableElement.TextBox.TextBoxItem.HostedControl;
        }

        public virtual void LoadQueryableSettings(QueryableAggregateDescriptionBase aggregateDescription)
        {
            this.textBox.Text = aggregateDescription.StringFormat;
            this.Text = String.Format(PivotGridLocalizationProvider.CurrentProvider.GetLocalizedString(PivotStringId.NumberFormatOptionsDialogFormatOptionsDescription),
                aggregateDescription.DisplayName);
            this.textBox.Select(this.textBox.Text.Length, 0);
            this.textBox.Focus();
        }
    }

You save 2 config, one with Report filter (1), one without (2), if you load first (1), if puts report filter correctly, but if you load then (2) - report filter still as on (1).
Also, if you load config with ShowFilterArea=true - it  stays visible if you load another config with ShowFilterArea=true 

Hello Alex,

While investigating the reported behavior I managed to isolate an issue in the Save/Load API of RadPivotGrid regarding the ShowFilterArea property. The default value of this property is not serialized, however this can be altered by adding a serialization meta data to the XmlSerializationInfo instance of the pivot. In this scenario the engine did not respect the added new data. Here is the feedback item and you can subscribe to it: http://feedback.telerik.com/Project/154/Feedback/Details/196273-fix-radpivotgrid-the-saveloadlayout-string-overload-does-not-use-the-radpivotg. The item is already in development and a permanent fix will be available with our next release.

Regarding the empty filter descriptions, in order to serialize them one should work with a DataProviderSerializer class. Currently our engine does not save the empty filters and we will consider modifying it so that even if the collection is empty it also be serialized.

I am attaching to this post a sample project with which you would be able to achieve both of your tasks. Please note that the serialization API of the LocalDataSourceProvider uses the DataContract and you would need to use our .NET 4.0 assemblies.

I hope this helps. In case you need additional assistance please write here or open a support ticket.

Regards, 
Hristo

Currently the words: Row, Column and Value are not localizable in the ScreenTip.

Currently they can be localized as follows:

void radPivotGrid1_ScreenTipNeeded(object sender, Telerik.WinControls.ScreenTipNeededEventArgs e)
{
    PivotCellElement cell = e.Item as PivotCellElement;
    if (cell == null || cell.ScreenTip == null)
    {
        return;
    }
 
    RadOffice2007ScreenTipElement screenTip = cell.ScreenTip asRadOffice2007ScreenTipElement;
    screenTip.MainTextLabel.Text = screenTip.MainTextLabel.Text
        .Replace("Value:", "ChangedValue:")
        .Replace("Row:", "ChangedRow:")
        .Replace("Column:", "ReplacedColumn:");
}

Add the ability to export to OpenXML format, specifically ".xlsx".

Add the ability to export in pdf format.

In the PrintElementFormatting event you need to be allowed to specify the PivotCellPrintElement.Text property in the desired format.

Workaround: use reflection to set the "formattedValue" readonly field for the PivotCellPrintElement.

It should be possible to persist the current configuration of RadPivotGrid so that when the settings are loaded, the settings of the RadPivotGrid should appear as when they were saved. This includes the column/row/filter/aggregate descriptors, the width/height of the resized rows/columns and the applied filters.