The GridViewSelectColumn is a very nice and useful feature, especially the possibility to select all items with just one click on the header. It would be great if there was the same functionality for the group header. So clicking on a checkbox in group header will select all items in this group (only). I know there are some examples (many years old) of how to do this, but it would be much better if it worked out-of-the-box.

Unhandled exception System.InvalidOperationException: The calling thread cannot access this object because a different thread owns it.
   at System.Windows.Threading.Dispatcher.VerifyAccess()
   at System.Windows.DependencyObject.GetValue(DependencyProperty dp)
   at Telerik.Windows.Data.SortDescriptorBase.get_SortDirection()
   at Telerik.Windows.Data.Expressions.SortDescriptorCollectionExpressionBuilder.Sort()
   at Telerik.Windows.Data.QueryableExtensions.Sort(IQueryable source, IEnumerable`1 sortDescriptors)
   at Telerik.Windows.Data.QueryableExtensions.Sort(IQueryable source, SortDescriptorCollection sortDescriptors)
. . .

You are able to resize columns using the columns gripper. The corresponding group will be automatically resized. We can provide a way to resize the column groups. The columns inside the group will be automatically resized with the group.

Add a separator element under the last pinned row, similar to the frozen columns splitter. The visual could be e horizontal line shown at the bottom border of the row.

The row arrangement is implemented correctly, but because of rounding errors, gaps and rows overlapping may appear during the WPF render phrase. This happens if the boundaries of the row containers use too high precision for its values (top, left, bottom, right). Consider improving this by rounding the boundary values before calling the Arrange() method of the row's container.

For example, we can create the SUM() function for the cells in the ViewPort.

At this moment, the Search As You Type functionality can be customized. We can expose several methods so that the user can override the default search behavior and implement their own.

The issue seems to be a bug with UI Row Virtualization since once I set it to False, it did not occur any more. You can also refer to the documentation on UI Virtualization: http://docs.telerik.com/devtools/wpf/controls/radgridview/features/ui-virtualization.html

When a gridview is placed in TabControl, the following CodedUI tests will fail:

Test 1. Click on a column header to sort by that column.

Test 2. Click on a drop-down button to filter a column.

Test 3. Drag a column to group by it. 

All DragVisualProviders for the RadListBox, as described in http://www.telerik.com/help/silverlight/radlistbox-features-dragdrop.html, show as a bare minimum a horizontal line that clearly shows where the drop within the list will occur.

Unfortunately the RadGridView does not even have that out of the box for its DragVisualProviders, so dragging elements within a RadGridView provides no indication at all to where the drop will happen! This seems like a very basic feature the RadGridView should have to support dragging/dropping within it (which also seems like a very common functionality).

Provide an option to group a column which is based on an enum by the enum value, but display the DescriptionAttribute or DisplayNameAttribute if existing.
So many times you have sort/group a column by its value like 1,2,3 but display the Description like "Delivery", "Ready", "Pickup". Of course I could add a column to my class which presents the DescriptionAttribute, but then grouping/sorting is wrong: "Delivery", "Pickup", "Ready". It would by much easier if there is an option like "UseDescription". There is something similar with Teleriks "EnumDataSource" which IS using the Description or DisplayName so it should not be that hard to implement the same logic for RadGridView.

It's so strange that Telerik's components don't support such basic mechanics of WPF...

Allow customizing the FieldFilterControl shown under the column header when the FilteringMode is set to FilterRow. Currently, you can customize this only via an implicit style or by looking into the gridview's visual tree in code. It would be useful if you can define a style per column.

Allow customization of selected unfocused state through RadGridViewRow style.