ProtoJ

They are probably talking about engagement. Depending on what level clutch you are talking about it could have a harsh engagement. On a rigid disc there is nothing to dampen the torque input to the transmission during the engagement of the clutch so it makes it kind of uncomfotable to drive on the street. My suggestion is that if you are not going to race the car then stick to a typical clutch and damped disc with an organic facing.

STAY AWAY FORM KEVLAR! It is false advertisement and does nothing for the performance of the clutch. It DOES NOT increase the coefficient of friction, it actually decrease as the temp increases. the only thing that it does is increases burst speed slightly. So what that means is that it will slip sooner and if you miss a shift it won't burst.