Although not owning a XR6T, I have owned several HSV V8's and, yes they are quick in a straight line like your T.
But for me, the Rex's are more fun for everyday driving. It's the handling and nimbleness that does it.
If you like traffic light sprints, keep the T, mod it and fall in love with it again.
If you like the twisties, and the WHOLE drive from A to B, get a Rex or Evo.
Also when it rains, the AWD wins hands down
As for dealers, I've tried to deal with SOP, but, in my opinion, they come across as arrogant and would not deal at all. Try City Subaru.
If the $$ are not an issue, definitely get an STI over a WRX and hold out for the new STI with the new donk. That's what I'm doing.