I have a stock flywheel and the 1600lb non-ceramic. It works great and on is on, off is off. Not like a switch - more like in a sports car. Quick and snappy. Really tough to burn up. You do have to make quicker gear changes, though, with it.
I had a Centerforce dual friction and all it did was act like a CVT at lower rpms. Kind of like the thing was only partially engaged/had a lot of slip. Odd feeling, though it never did burn itself or anything. Not my "thing" - I want engaged or not engaged.
