I just put one on my car this weekend. I scored a great deal on it thru SVTP. I paid $350 for a polished set up that had about 3K miles on it. Throttle response is wicked. Its a whole new experience trying to drive it again. Cruise control doesn't work that great which I expected (larger throttle plate = needing less gain and integral in the CC PID). Power wise it may have picked up a few, that's hard to tell because this weekend was the first time I've driven in a while. It was fun with how snappy the car is now.
Cliff notes: If I would not have gotten a good deal I would not have bought one.
Your local to me, I work in New Lenox. So if you want to go for a test ride I'd be more than happy to have an excuse to drive my Cobra to work!! lol. Let me know...