Although the Kawasaki i had did burn up the road with the speed, and although it rusted, it was incredible. It would easily do 60mpg, and i was a very "throttle happy" rider on it. It never complained, the engine never showed any signs of trouble whatsoever, and the bike was 100% stable at the bottom end of the M5 motorway exceeding 100mph. It is a incredible machine, and i am trying find another Kawasaki GT550.
Rust was the main and only problem. Also my size was a bit of a problem, but i didn't care, and i enjoyed riding it so much i didn't care.