Available in LIB version 2016.3.1121, it will be also available in the 2017 R1 Release.

Enhance aggregate functions (like Sum) in footers so they support expression columns in RadGridView. 

See the attached project. It works for DataColumn, but raises an exception that no suitable generic Sum method could be found when I set the Sum footer for an expression column.

It would be very nice to have a "transpose" functionality in RadGridView. There are ways to transpose data instead of GridView, but this way it would be difficult to configure bindings, styles and other parameters. PivotGrid isn't suitable in this scenario because of lack of editing.

There is an example of what is needed: https://rotatedwpfdatagrid.codeplex.com/. I was successfully using this example with a standard WPF DataGrid, but I don't know how to accomplish this in RadGridView.

There are already a few threads about this feature:
http://www.telerik.com/forums/transposing-columns-and-rows
http://www.telerik.com/forums/radgridview-can-be-transposed
http://www.telerik.com/forums/displaying-grid-data-in-column-row-format
http://www.telerik.com/forums/reverse-column-and-row-in-the-grid

Thank you!

Fixed for GroupRenderMode="Flat".

ArgumentNullException

The fix will be included in LIB version 2015.3.1026.

The fix will be available with Q2 2015.

Add the "does not begin with" and "does not end with" to the list of filter parameters

The problem was initially reproduced by TestStudio users. It can also be reproduced with a codedUI test where the editor is searched by its AutomationID.

Error Message:

Microsoft.VisualStudio.TestTools.UITest.Extension.UITestControlNotFoundException: The playback failed to find the control with the given search properties. Additional Details: 
TechnologyName:  'UIA'
ControlType:  'Text'
AutomationId:  'CellElement_2_1'