Thank you for writing.
We did the following test: Created a new project, added references to Q3 libraries, added a RadTabStrip
to the main form, and pasted the code you provided in the form's constructor, immediately following the call to the InitializeComponent method. The program was run in debug mode. The times reported ranged from ~0.43s to ~0.64s.
There's probably something else causing the performance degradation you are experiencing. Could you please send us a small project reproducing this specific behavior? This will help us track down any potential issue much faster.
If you have any additional questions, please contact us again.
the Telerik team