I still play T1 for World Assasins (biggest newb name ever) on the 5v5 ladder. Still a good time, would be better if I didn't suck though.
I don't think it's a really fair comparison between the tribes series and PS. I think PS is what Dave really wanted to make with t2, whereas tribes has always been about individual achievment as part of a team, sort of like baseball, PS will be more like football, the whole team needing to be in sync in order to succeed.