I am up about 10% on mileage, which means its paid for itself in the year I have had it. I don't think I could go back to non smarty, when i get the oil changed etc I return to stock and the truck feels so sluggish, I am running an older program one from early last year, maybe there is a better one?? the smoke is a bit much in the summer, however since its gotten cold, I notice way less smoke on the bumper and quarter panel and prolly about 1/4 of the smoke I see during the heat of the summer. being able to mash the go pedal getting sideways while jumping out into traffic is awesome, tiresmokeing 360 powerbraking donuts are fun too when I am about to put new tires ons. I try not to really get into it below 2k rpm as I don't think the trans likes it. I sure wish I had a modded transmission so I could unleash level 8 or 9