The 2000 through 2002 are basically the same bike (i've got the '00). obviously there are the cosmetic differences, but I think beyond that there are no other differences.
As far as comfort, I've ridden of a few of the other 600 class bikes, and I still think by far, the Kawi's are the most comfortable. I can easily put 350-400 miles on mine, and no pain what so ever....I couldn't say the same for an F4i with its cardboard seat....
As far as performance in the class, they are all basically within the same area. The kawi has been scoring last in the mags for the last couple of years, but that's only because they haven't made any significant mechanical changes, whereas you have the F4i, the new GXR-600 (FI now I think)....but frankly my opinion is the mags can go screw themselves...they're all corporate bought opinions anyway....you ride what you wanna ride, and what fits you (style, looks, price, comfort, etc...)
Just my .02
If you've got specific questions about the bike, I'd be happy to answer em...I've got about 9500 miles on mine since March 01, and have done all the wrenching myself, with the help of a few friends.