I've been looking at handheld programmers and wondering how effective they are. I've got a 02 Z28 LS1 w/auto trans that has an SLP RAM air kit (cold air induction/smooth/KN filter/smooth air filter lid/bellows) plus Magnaflow CAT back exhaust system. Not planning to do much more as this is my daily driver. Perhaps headers somewheres down the road.

I've been looking at the Hypertech, Diablo and SLP models and don't see much a difference in features. Key one's from my perspective appear to be: trans adjustments for firmer shifts (something that I'd like to change since stock is pretty mushy), tire sizing (planning to change wheel/tires soon), and what they all call performance tuning optimization.

The one area I'm most curious about is the performance tune optimization since it must assume some sort of baseline spec on the engine/induction/exhaust.

Any feedback would be really appreciated. Also any recommendations on where to buy?