US-1
Banned
You will want to go and sit on each bike to see how you like it IMO. I like the way the GSX's feel, and the Honda's. Out of those 4 it would a toss up between the GSX and the 600RR. I have always loved the 600RR's. IMO you can never go wrong with a GSXR though. Plenty of parts for the bikes.
I agree with Jarrod. Go put your butt on every bike you consider. Each one will fit different in every way. I have been riding for many years and all of those bikes make good power so pick your addiction on what feels right. You may also consider the GSXR 1000. It has an option to pull the power back in stages. It's like having a GSX-600, 750, 1000 all in one bike.
BJ
I was talking to the kiddo about it last night. Went something like this.....
Me: Might start out on something small like a Ninja 250.
Mike: No way, Dad.....Gixxer 1000.
Me: Well Mike...I haven't ridden since I was 18 so that might be a bit much.....maybe a Gixxer 600.
Mike: Aawww hell, Dad.....Hayabusa!!!!
I'm thinking the little shit has seen my life insurance policy and now knows how much I'm worth dead.
I'm not so sure he can............Is THIS why u didnt finish that guys motor? Hahahaha. (hmmmm, he can take a joke, right?)