My developer friends --
I have just been informed by Telerik support that you CANNOT perform a group sort on anything other than Ascending or Descending of the column being grouped on.
Imagine needing to offer a feature in your product that Groups by Salesperson and totals all their sales across product lines and geography. Now, let's also say that you wanted to sort all of your Salespersons by their total Sales,,,,YOU CANNOT DO IT !!! But you can sort your Salespersons alphabetically. Tell that to your users. Tell your users that they will have to look through the list to find out who your top sales people are !!
If you vote for my feature request, by virtue of the power of democracy, you can tell Telerik to offer the very feature that has existed in Excel for years. Here's the link:
http://feedback.telerik.com/Project/108/Feedback/Details/165036-group-sorting-by-totals-of-other-grouped-items
Go there and vote for this feature. One day YOU TOO will need it, but be stuck without such a basic feature.