Get the gixxer, doesn't matter what size, they are ALL fast. I've seen 600's pull 10 flat in the 1/4 beside me on my 750...Its not the motor as much as the rider...90% or more of most riders can't take their bikes to the limits, so size doesn't really matter. ONly after 120mph, then the 750 and 1000's kick in hard over the 600's....Don't buy a harley, they are heavy and can't be layed over to far or you'll scrape the foot pads. I did this once going around a corner at 50mph on a back road. I wasn't even that far over. Scared the hell out of me. What if I had to avoid a car or animal. I'd end up laying the bike down because of all the shit hanging off it will be rubbing...f*ck that, they are worthless. They don't ride any smoother, just a different body positioning. For twice the price and half the handling and performance, Harley are way overrated......Then you have to add oil on every ride....