I agree with elesbb: 6.1 is more stable, but 6.5 has the features. I would personally recommend installing a custom ROM of 6.5
There are quite a few awesome ROMS with excellent tutorials and active users ready to help you.
The ones I personally like are Sharkie's ROM, the Energy ROM, and the Mr. X ROM
You can find them all in the
CDMA TP2 Development sub-forum
Welcome to the TP2 family!