Forgive me, I'm sure someone may have addressed this question before, but I can't seem to find the answer on this board.

The Handspring/PalmOne web site says that using the Cingular version of the Treo 600 on another GSM network such as T-Mobile's may lead to performance issues such as slower data rates. Is there any truth to this or is Handspring just trying to protect sales of the T-Mobile version (which is still infuriatingly absent)?

Has anyone found any other differences in the Cingular version besides these possible performance issues and the Cingular branding?