I am running a clutch specialties sprung 6 puck. I can honestly say it is the best clutch i have ever owned. I had an act extreme with a full face disc and it sucked, harsh engaugement and wore out around 7k. I also had 2 spec clutches, 1 sprung 4 puck and 1 sprund 6 puck. Both were halfway decent IMHO, the 4 puck was a bit grabby though.