Honda's XR650R single is supposed to turn 102 mph or so in the 1/4m (on knobbies ???), so a Kawasaki 650 street version will most likely more than keep up with traffic!! Honda's owner's manual cautions to check two bolts every time you ride and to locktite them. Your K may not vibrate as bad, but it might be good to read your manual thoroughly.
Just remember, everything on the road from marbles to semi trucks can kill you when you are on two wheels. The only safety you have is between your two ears!!! Enjoy the ride though.