Restricted Busa is 183, unrestricted (TRE installed) it'll hit 186-189. All you need is a tight tuck and a long road.Wow, a whole 3mph difference... and more expensive... and kind of ugly.
And what happened to the Busa's 189 top speed? I could be wrong. But I know I read that it would at least do 186! Anyway, I'm happy with the Busa. I've never been a Kawi fan.
Funny though, last year Cycle World compared the ZX-12R and the Busa. Guess what the top speeds were ... Busa = 183, 12R = 186.