Between filtering is not working when RadGrid is bound to ClientDataSource. Trying to programmatically filter a date range will cause a JS exception.

The problem for which the bug was opened was not actually caused by the RadGrid. It was triggered by wrong configuration of the test sample. The parent container which held the grid had disabled ViewState in which case it is expected for the filter values and filter functions to not persist.

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.

When the grid has no paging and all the groups are collapsed its good to have a paging defined within grouping to display all the groups in the same page as well can browse through the items within the group with paging defined.

As per the current implementation of the RadGrid control, if we set the CurrentFilterFunction, that will be used for that column and even with no value, the same filter function will be used (specified in the CurrentFilterFunction).

This is not user friendly and one should expect that "NoFilter" will be invoked when there is no value.

There is no possibility for invoking the "NoFilter" command when the following properties are set:
ShowFilterIcon = False and AutoPostBackOnFilter = True

please refer the following link for more information:
http://www.telerik.com/forums/filter-not-resetting-if-filtervalue-is-empty-in-client-side-filtering

Ability to add custom buttons to the command item collection. 

I brought this to Telerik's attention 4 years ago. The grid Pager is a poor location for the built-in loading image because it is not clearly visible in a number of scenarios. First off, it is small and tucked in the corner, which makes it hard to see. But there are other scenarios where it is completely invisible. 

If the grid height is fixed and larger than the screen size, the entire pager is not visible unless the user scrolls the window. So, the loading image will not be visible when users take actions like sorting/editing/deleting/filtering which tend to occur towards the top of the grid.

And, if the grid has Paging disabled, then the pager and built-in loading image will NEVER be visible.

I understand that one can add a custom loading image which would work better. And if asked, Telerik can provide a couple dozen lines of custom javascript which will move the loading image for a grid. But If your project has a large number of grids, adding code to each is untenable. And at the end of the day, this should be a built-in feature of Rad Grid, not something that needs to be hacked to work appropriately.

RadWindow used to have a tiny loading image in the status bar which was invisible in a number of scenarios, most notably when the status bar was disabled. The Rad Window team saw fit to move the loading image to the center of the Rad Window where it belonged. This was years ago. For some reason, the Rad Grid team has not seen fit to do the same. Why is the RadWindow team aware of and responsive to concerns about the usability of their control and the Rad Grid team is not?

Is any option to use RadGrid in disconnected mode. So when user lost connection with internet(intranet), he can continue to work with grid - add new record, edit records. In html 5 appear such technologies like HTML5 Storage,Web Sql. Is it any way to interact with them?