well the cermetalic is the ones tilton sells for the 1jz for street use. its not the easiest clutch to street drive but is driveable. friend of mine has been running this clutch on his 1j for ~1-2 years. tilton says the cermetalic can withstand the heat of slipping where as the metalic cant as its so thin. i needed something that would hold 800+ hp and not be so stiff id have to worry about crankwalk.