I also have the 03 type-s. I have definitely noticed the lack of power while the air conditioner is running.

Even after installing an injen cold-air intake (which sounds and performs excellennnnnt) the power slip is very noticable while the air is running.

My solution: Simple... Dont turn AC on when fast acceleration or racing is ur goal, you'll only piss yourself off...AC units rob horsepower of all vehicles anyway