A bit off topic I know, but I have a lightened flywheel on my 888. Combined with spot-on cam-timing it really picks up well - almost like an inline 4, but still with heaps of torque.
Admittedly I did have the whole crank/piston/rod/flywheel assembly balanced.
I haven't really noticed any problems on the road, but it could be the advantage of injection (FIM-chipped too) over carbs...