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.
If you look at the HTML that is producted for this control, there's the User Interface portion, and then in Javascript there's a structure that maintains the value/text combination.
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.