My 250 ninja is perfectly happy at 75 mph and 9,000 rpm for miles on end. The bar end mirrors never blur. quite smooth actually. I did go up a tooth on the front because of the REALLY low first gear. It will pull 13K in 6th on a flat with no head wind. I like to think it punches well above it's weight.
My 2004 Buell XB12s feels quite buzzy at 70 mph and 3,100 rpm. It will numb your feet on long rides and tingle your hands. It handles brilliantly, but feels much heavier than the baby Ninja.
I wear earplugs, and the little one wears stock pipes. I can barely hear it on the road. The Buell wears a race exhaust which is very deep but not really loud, rather pleasant actually.
My pick for most rides is actually the baby Ninja because it is so much fun.
The older I get, the faster I was.