The TS definitely makes this a completely different car and since it's not centrifugal based, it doesn't suffer from heatsoak. 2.5 years and 20k later it still hums right along. I think it'll accelerate the deterioration of certain parts (MAF-haha, guibo, tires), but getting 370 rwhp at the dyno is well worth it(and the TS sound is to die for). I bought mine from Active Auotwerke for $$$$, but they don't sell it anymore. I think they have a centrifugal-based one now that produces the same hp.
Either way, I like it and it was easy to install, believe it or not AND my engine bay doesn't look all modded out. (It actually passed smog in CA, too. woot!)
Wasting those retarded STI's are always fun.
I'll post some pics for ya in day or two.