i had a stage 1 in mine, was a massive pain in the leg (seriously, if i drove the thing in traffic too long, my left leg and foot would be a bit sore). was also very on/off with not much slip.
i hear the stage 2 and stage 3 are better, more driveable clutches, but never had one. the stage1 i had stayed in the car about 2 years until the motor came out and i replaced it with an frpp king cobra, lots fewer complaints with that one.