I've experienced vibration / pins and needles in my right hand on every bike I've owned (ER6, GSXR600, Fazer8), I think its more to do with the way I grip the throttle rather than the bike. Ive found that trying to relax my hand, like I do on the left helps, still get a dead hand from time to time though. Funnily enough I also get in when I ride a push bike!!