I have Stage 1 and have put about 3000 miles on it. I love it! Big horsepower and torque gains. No loss of mpg's. Turbo spool up is immediate and the turbo whistle is much more noticeable than stock. The only complaint I could make is that you can feel the turbo hit hard and then a second or 2 later you can feel the boost drop off. I love it though. I'm looking forward to stage 2 because this thing is already a beast! FYI, I have the 8-speed. If anyone is on the fence I'd say go for it!