Better than Cobb's!
I had the Cobb Big SF intake for a while and it was very inferior to what GrimmSpeed has to offer. The GrimmSpeed air box is a much cleaner setup, hence the "stealthbox" moniker. No fitment issues whatsoever and seems to be louder than Cobb's. Yes you need to get a pro tune with this intake but it would be all worth it in the long run. Don't make the same mistake I did and settled for another brand. Just get this the first time around. Installation was very simple although I did it with ramps to access the bottom (it's much easier than doing it all from above. My car has all sort of GrimmSpeed goodies now: intake, j-pipe, pulley cover, charge pipe, top mount intercooler, and even their Delrin shift knob. Gotta love GrimmSpeed :D