THe fact that an aftermarket exhaust produced power on other cars has no bearing at all on the F20c. This engine is producing 240 crank hp from 2L stock, that's not an accident. Air is flowing about as well as it can through this engine with the stock parts.
The only advantages to an exhaust would be weight savings (a single Ti exhaust can drop 50lb off the car), looks (nothing wrong with wanting to look good out there) and sound. I agree that the Invidia is a bit loud for daily use. But, compared to some Ti singles I've heard, it sounds like a bee farting
