with client-side databinding when setting sort/filter expressions on button click and then calling the rebind or set_currentPageIndex methods the control makes multiple requests to the web service.

Underline style does not work in ExcelML export in RadGrid. Throws an exception.

RadGrid VirtualScrolling does not scroll to the bottom when StaticHeaders are enabled. The issue could be observed in the attached project.

For RadGrid (and other similar controls) it would be nice to be able to simply add AutoHeight="true" to the elements markup to make the grid calculate the browser height and adjust it's own height (including the scrollable DataDiv inside it) automatically rather than having to resort to custom javascript to achieve the same thing.

ie: activate AutoHeight on RadGrid and simply set the distance from the bottom of the browser window to allow for footers, etc. and have that distance maintained even when the browser is resized.

Height and ScrollHeight can only use explicit values - not percentages - which is kind of useless if you want the grid to occupy 100% of the available browser height across different devices. http://www.telerik.com/help/aspnet-ajax/grid-height-vs-scrollheight.html

The new RadGrid Filtering (Checkbox list) is great, but...
1) it will be great if, upon RadGrid Databinding, the filter gets a list of unique value for that column: that is, most of the time, how we populate the checklist.
2) Today, there's one Event "OnfilterCheckListItemsRequested" that is fired whenever a listbox needs to gets its list. Then you have to put in the event Handler the logic to find out which column called, and give back the specific column checkbox filtering list.
IMO, each column should have a distinct EventHandler for this. 
And BTW, if in the same radgrid you mix the new filter and the old ones, the old ones get an empty box instead of the default filters with option "FilterType=checklist"
Even if you choose filterType=Combined, there's a difference with the standard 'Filter way': instead of having directly the filters, you got to pass thru a single menu "filter options" to find the filter menu.