Hey,,,, I just installed the Hypertech programer on my 03 GMC Duramax,,,,I set it to level 2 and OMG, it is unbelievible! I thought this was sort of snake oil, but no way!! When I started the engine after programing it sounded like normal,,,,no differance... I pulled out of the driveway and it felt just like it used to (good thing I guess),,, drove up the road and it felt normal untill I started pressing on the pedal! The truck accelerated agresivelly !! I am impressed and I can't see any reason to go to level 3..
Anyone who needs more power is using it for strictly recreational purposes only. I can't believe what a differance this made. The power was linear, smooth, and extreme. Am I not in touch with reality or are people that complain about the power delivery of this programer being unrealistic? I am a happy camper to say the least!!