Honestly, the stock clutching from Yamaha for the Apex is hard to beat. We've always had stellar belt life and clutch reliability.
my stock 2011 clutching was great for trail riding but i do a fair amount of offtrail so i re did mine for more bottom end grunt.
Thanks guys. Question for you tho... More bottom end grunt or more midrange? I would think a studless shorty would have traction issues punching it on a 30 mph roll, no less at speeds below that.