i had a hypertech chip in my last hoe and it was ok - bought the truck used and it was already in it and i really didnt mess with it that much so RIZZ might know more
BUT
i have heard some good things about black bear tuning and im looking into that - no experience just been talking with the people at black bear and they have alot of good things to say - also its more of a custom tuning to your specific tahoe whereas hypertech is just a general chip.