I used a postage scale and weighed the stock piston and the 97mm Wiseco and Woessner pistons and pins (no rings or clips).

The stock piston was 1LB - 0.8OZ, the 97mm Wiseco was 1LB-0.3OZ, and the 97mm Woessner was 1LB, 1.2OZ.

Since the difference between the stock 94mm piston and the 97mm Wiseco is only 0.07%, I believe it is not really noticeable. (I don't know the weight of the 95mm or 96mm Wiseco).

I currently have a 95mm Wiseco in my bike and I don't notice any difference in vibration when at a steady speed - but under full power the engine does make a more noticeable "pull" and the power pulses are more pronounced and vibrate the mirrors a bit more (until you roll off the throttle)....partial throttle seems to make very little difference in vibration - however the increased compression ratio makes the bike slow faster when you roll off the throttle.