I just changed my minerals to Motul 5100 15w-50 synthetics, so far so good didn't notice any difference. Synthetic oil is superior compared to mineral oil in every aspect, and if it is made for motorcycle use, it is usually made for wet clutches too. Oil being too slippery is a BS in my mind, maybe that some synthetics has that kind of additives in it that it makes your clutch slip, but that isn't reason of oil being synthetic.
Good writeup that made me try synthetics (or then I'm just *******) ->
http://www.post610.org/truth_about_motorcycle_oils.htm
What ever you use, change it reguraly with fresh oil filter.