the decrease in gas mileage was minimal for me. As long as I keep it under 100mph for long distance road trips, i see mid-high 40 mpg. in town i still get well into the 30's. But honestly, if i wanted good gas mileage, i would have bought a 600.
I certainly don't care if my bike will only do 169 mph now. so what. I do like the fact that it does 0-100mph much quicker than before and the added torque is quite lovely. Next is going up on the rear sprocket.
Rich