I do not love the Telerik controls, but I do tolerate them. They each have their own set of issues.
One recent issue I had was with the Telerik RadComboBox SelectedIndexChanged event. The SelectedValue property was always blank. Only the Text property was valid.
This is unlike a normal HTML combobox that has all of this data right in the HTML.
I had to add the AppendDataBoundItems="true" tag to the telerik:RadComboBox control in the page. Then, SelectedValue was correct.