I drove my friend's Z with the SZ clutch yesterday and it was Stupid soft. Granted his car is originally a TT and has clutch assist, and my car is normally a NA, so no clutch assist. I doubt it will be that much stiffer thou.
The OS will go up for sale or sit in the Garage intil I finish with one of my other Z's.
The chatter from the OS does not bother me at all, it only chatters when the clutch is pressed in.