I have been running one on my sled for a couple years now. Just replaced the bearing, it didn't fail, just wanted to freshen it up. i do like the extra support on the PTO side of the crank. I cant imagine the force the clutch has spinning 8000 RPM, if it isn't balanced perfectly.
FYI, the replacement bearing was $50, so 99 for the whole thing isnt bad at all.