I have one with a needswings CAI, I believe that it made 8-10 hp more. 8-10hp usually feels like a little throttle response. The engine feels like it can breathe better. I didn't notice a huge difference as far as getting thrown back into the seat, but the car feels peppier in situations where I would expect it to bog a little bit. I feel like the car is a little easier to drive now. The TB's larger opening is only beneficial at times where the smaller one would be a restriction. For $200-$300 I think it's worth it, but it wouldn't be my first modification. The more the TB becomes a restriction, the more power it will make.