I did a ton of research on the EZ kits before I went Gen III hemi, DO IT...(I will be using the FAST XFI self tuning on my hemi) They are great systems, If you read from guys that have it they not only make more power, but have better start-ups, crisper throttle response, and BETTER MPG. How could one go wrong. I have a friend that runs the XFI with the self tuning in a racing ap. HE says he doesnt use the self tuning because he has dyno access, but that it does work well. Horsepower TV has done a write-up of these kits, as well as otehr shows. Abodyjoe has one I think, and there are other members that do as well.