Thank you for this question. Yes, I can confirm that the solution to use maps (Dictionary or Hashtable collections) to keep your tree view settings is the best solution in this scenario. If you have any additional questions regarding this issue, I will be glad to help.
the Telerik team
Q1’11 SP1 of RadControls for WinForms is available for download
; also available is the Q2'11 Roadmap
for Telerik Windows Forms controls.