I just put 220 miles on my UUC Organic clutch, and here is what I noticed:
1) My tech had to send the first clutch back cause it was off center. It is smaller that stock apparently, but the material is more aggressive. My tech said it also looked like a Clutchmasters disc.
2) It shudders when being slipped in first. Not bad, and quite livable.
3) When you let off the gas, and decelerate down through 2500 rpms, the whole car shudders for about 200 rpms, then stops!!! This SUCKS.
4) Many more noises like as if a light flywheel were installed. Anoying, but a reason for an Eisenmann...

5) Grabs the way the stock clutch should: Flawlessly, with no slip.
6) Clutch pedal feel is LIGHTER, but you need to really make sure the pedal is fully depressed or you will grind gears...
I will see how it holds up. In the mean time, I like the performance, but am concerned about the odd shudder.