Searching by date range is a very common use-case in most business applications. I need a From and To calendar controls in the row filter.

I would advise Telerik to put this functionality on the roadmap, else the row filter functionality is so restrictive as to render it useless. 

I am having to roll my own filters above the grid because of this one omission which is a real shame because the rest of the Grid functionality is so good.

(I don't want to use filters in column headers because I don't like the fact you loose visibility of what filters are on - probably the reason for the grid rows introduction)