i just installed the ITR cat and exhaust onto my GS and it sounds pretty good with my AEM short ram. I have a vid of it if anyone wants to hear it just IM me on AIM: ji1984

from the butt dyno, it feels like i did gain a little. i noticed that the needle went up faster than before. but overall, i'm pretty satisfied beause the ticking noise that our integra get from the heat shield of whatever is gone too.