How many of you are happy with this product for Truck performance tuning? I bought one the other day to improve my trailering. I have a '02 Chevy 2500HD 6.0L Auto. and have only tuned the gas octane and transmission shift firmness. I have not messed with adjusting the shift points and would like to know if anyone has a similar setup and what you have the shift points setup for heavy trailering.