I used my Competition Pro Mini in an Amiga 4Player adapter in the Parallel port. I seemed great but if I moved the stick too fast the PPjoy drivers seemed to lock up pointing constantly left. The only way to stop it was a reboot. If I played a game with fast joystick movements it would just happen again almost immediately! I could even get it to stick left in the joystick properties panel.
So, I went back to my PS2-like pad.