The documentation wrongly says that the grid will perform all server operations of paging, sorting, grouping, and aggregating whether bound to an iQueryable interface or a DataTable (http://docs.telerik.com/kendo-ui/getting-started/using-kendo-with/aspnet-mvc/helpers/grid/faq).
It turns out, after an extensive support ticket, that the documentation is plainly wrong. I have been told that only the COUNT() aggregate is supported when doing server side operations and bound to a Grid.
My request is that this gap in functionality should be fixed so that server operations work for both iQueryable datasources and DataTables.