First, let me start with the fact that if your custom code for retrieving the data that will be bound to the grid requires great amount of time (with the 50 queries), there is nothing that could be done from the RadGrid to increase the performance, because the control will work with the provided data and has no control over the way the data is retrieved. Furthermore, on each complex operation (like paging, sorting, filtering, editing, etc.), the grid will require the data once again and will recreate its structure. With that in mind, if you need to increase the performance you will have to modify your logic for retrieving the data or change your data sources.
As for other products that you could look at, the Kendo UI has equivalent to the UI for ASP.NET AJAX suite controls:
Hope this helps.
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