Now done 2k miles with it in the gearbox, no difference whatsoever, still noisey and clunky, as it always has been. Waste of money, Going back to the treacle next change.
I can't say that it ever had any effect on my 1100 gearbox, it's just as tractor like whatever it gets. I'll keep using it as it's unlikely to do harm. Hopefully the benefits of fully synthetic will be in the longevity of the box.
I intend to keep this bike for a long time, so that's important to me.
Don`t go back to mineral oil in your g/box once you have used fully syth ,as could cause damage in the short term!,
If you must go back (why), then go the semi-syth option on the way back.
I got mobil 1 fully syth and it as made a smoother g/box for me.