Spec is probably the best choice for an aftermarket clutch for our cars. They are the only clutch mass produced that uses an actual aftermarket pressure plate. Others like Centerforce just reuse OEM pressure plates and slap some paint and stickers on them, and on some models they might actually pop some counter weights on the fingers of the pressure plate *Oh boy!*
Stage I is a great clutch and actually surpasses stage II. Steel backed organic lining is by far a better clutch material in every way, UNLESS you are looking for a clutch that won't bite into your flywheel bad enough to allow you to switch out clutches without machining the flywheel (tractor and semi-truck guys love them). Kevlar sucks for brake and clutch material period. It glazes over when it comes into contact with oil of any kind. Heat will make it much more brittle over time, and it doesn't bite nearly as hard as steel backed organic lining. Where as steel backed organic lining resists bursting and tearing under high heat.
Stage III should be for FI applications in all reality. Ceramic BITES HARD!!!! But it's overkill for a normal application and would just cause more harshness than you need, not extend lifetime.
