Well I installed my Superchips 3815 today with the 91 Octane Performance Tune(I'm actually running 93 Octane) on my '06 SC/SB Hemi w/3.92's with my only other performance mod being a borla exhaust. First let me say the difference was night and day. I still cannot light up my tires from a standstill but the difference in throttle response and the firmer shifts are amazing. Instead of tumbling through the shifts when stock it actually feels like it is slinging you forward. I already have to be more conscious when going around corners as to how much peddle I can use. After only one day if I had to drive my truck without it I would be pretty depressed. Now, I'm sure the little cold front that moved through knocking the humidity down didn't hurt either. Just wanted to give my opinion on this product. If you are on the fence about this don't think twice, great bang for the buck. Can't wait to get the 4.56's put in next month.