I've had a bunch of exhausts and the best one I've used is the GReddy SP Elite. The ARK is really nice, but the midpipe resonator is a bit low. I'm also not a fan of the fake blue tips on the ARK or the CNT. IMO, the flared, double wall tips on the GReddy are the only way to go. They look so much classier!
Despite all those good things, I'm actually selling the GReddy right now. I will be going back to the stock exhaust for a while because I need $$$. If anyone is interested, here is the listing:
EDIT: It looks amazing!