well...with all of the other things i'm doing to the car...it kinda helps...if you look at the whole picture instead of just the ECU and what that'll do for the car. i'm modeling my car after a friend's...and when he was finished, he was getting 30+ mpg in the city...and he did have the fasted p5 in the area...so i think i'd rather have the mp3 ecu...besides, i just drive to and from work...so the gas isn't that big of a deal.
but thanks for your insight...yeah, it doesn't seem worth it...but it will be.