Nitehawks are great but those 650's (the newer 750's are chain drive) are prone to eating their cam chain tensioner, #4 crank bearing if you dont use the centerstand much and if the strater clutch ever goes ...the motor is toast cos it has to come out and split and entirely taken apart to get it. Plus the bike also is heavy, not that quick, has rather poor handling and is entirely devoid of personality. The good thing is that it has hydraulic valves so no valve adjustments needed...Still I'd take the GS over the nitehawk. The newer 750's are the same in all respects except they dont have shaft...they are chain.
Cool.
Srinath.