I would like to suggest that a more intuitive clear filter option be used on the Filtering columns in the RadGrid.  Currently, I have to select "No Filter" from the Filter list of options.

Instead, I believe the Filter should be provided to be more intuitive similar to other applications such as Microsoft Access, Excel or Google Search.

In Microsoft Access or Excel, I simply unselect the Filter icon to remove the Filter.
In Google Search, I simply click the X icon next to my search criteria to remove my search text.

Either of these methods should be adopted so that the overall end user experience is more pleasant and comparable to filter capabilities in other tools and products.