Well, I won't be nice on this one....I have a CYA PCM, I won it at a local club event. I wish my stocker was still in. The only improvement it made was in the shifting. Mike's (CYA) philosophy to tuning in more power is to lean the curve, and not mess with timing. So stock timing, speed limiter still there, no skip shift, lean 02's; a truly winning combination! I guess if your on a 3.4 pulley, with very little mods it's better than stock, but soon as I started dipping below 13.5's the PCM has been an extremely limiting factor on my car.