Not sure if they had an issue with the single disc also, but the dual style, my friend had a problem with pins falling out. They actually called him and informed him of the problem and sent him a new clutch for free.

Myself, I run a phoenix fritction, full ceramic single disc and I tow a lot, have 33" tires and an edge box set on 5 and 100hp injectors... never slipped. Can't beat em for under 400 bucks!