Silkolene Full Synthetic... Made the Tranny feel 100% better, Buttery smooth, Zero Clutch slip, improved power and piece of mind cause you know your running something actually built for a bike in your machine. Why Mickey Mouse around with your bikes life Blood??? Spend the Money, Avoid any oil (DINO or SYNTHETIC) with a really high molly count and you shouldn't ever have any troubles with clutch slipage.
Moving to a premium full synthetic blew me away by the difference it made in the tranny feel, and smoothness. Don't skimp and don't be suckered in by some "voodoo". Do some homework on your own, and check the data for yourself. Unless your like JC and change your Dino oil every week or so, synthetic would probably be an ideal choice. Especially in High Heat High Stress environments... My .02