Welcome to the site and congrats on your purchase. I've heard nothing but good about the GMPP exhaust, but I don't have any personal experience with it. As for performance, it's all relative to your experience. If you are coming from a 1979 Ford Pinto then the 2.2s performance will be stellar, if your last car was a Ascari A10, you're going to be disapointed.
Either way, just enjoy the car and have fun because that's what's important.