For those that have "clutch sticking" issues, I have a few questions....
Did the clutch stick under WOT or did you experience it during "normal" driving?
What symptoms / indications did you have with the clutch sticking?
I am asking because I am suspecting I am having a similar issue that could be caused by the spring. I have noticed sounds/vibrations that indicate the clutch (slave cylinder) is engaging slowly causing the clutch to chatter or slam (as if I dumped the clutch).
I am thinking it could be the assist spring is not allowing the pedal to come up as fast as my foot is engaging the clutch.