holding power, how much it shocks the drivetrain, price, and driveability. higher number= higher torque capacity, but stiffer pedal feel, harder engagement, and rougher on the drivetrain.
i have a dual friction centerforce clutch its weird i dunno how it works but it hold 100% more then stock and its not harder to push the clutch pedal is at all
you have to keep in mind that each clutch companies' "STAGES" don't all equal each other. Each company has their own stages that they do and can differ in aggresiveness and parts that are included.
