Performance... Depends on the application. I think I have read before a few places that if your running purely n/a then you don't need anything over 2.5 piping. Turbo app requires generally more. I have the greddy and I love it. It's loud, it breathes, an looks awesome.
I like the fi exhaust looks. It seems like a lot of people think the performance is better. Maybe it's just tuned to stock ecu specs more so than other exhausts. That's my guess. They are all pretty much built the same. So it really comes down to looks for me. I like mine
