Hi Eliyahu ,
RadEntityFrameworkDataSource is mainly created for the needs of RadGridView, RadDataFilter and RadDataPager. When its up to RadTreeView it is best to bind it to ObservableCollection<T>. You can check out these approaches:
RadTreeView Binding to WCF Service
RadTreeView Binding to Ado Net Service
As for the response time, we highly suggest you to open a support ticket instead of forum. Then your 24-h response time is guaranteed. Thank you for your understanding.
the Telerik team
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