How does the Kawasaki Ninja 750's compare to an f4i? My buddy has a 750 and I'm just wondering how my 600 (f4i) compares. I think he has a 98 and I have an 02.

Honestly,
Your 600CC would have the straight line advantage. The ZX-7R is an old and outdated bike performance wise. They are quite heavy. Probably about 60 or more pounds heavier then your 600. HP wise, the 750 might have alittle more, but the weight makes up for any hp advantage. The ZX-7R can be an excellent bike for the twisties with the right rider. Looks wise, I have always liked the looks of the ZX-7R for some reason. I have heard it's a comfortable bike for touring as well.