The flywheel I just removed from my sapphy is almost blue all over not just a spot, I had zero juddering, and a perfect clutch save for the rattling springs, AP clutch/BB.
Is the cable 100% free ?, on the cossies the cable has a teflon inner that tears and jams up the cable so it releases in spits and spurts, causes juddering, just a thought.
Did you us a new pressure plate/diaphragm ?
tabetha