I rode both the S and the R models. Great looking bikes, and comfortable. Other than that, well... Both seemed greatly down on power compared to even my Gen1 Busa. In fact we ran my Busa against the S model up to about 90 mph from a slow roll. It wasn't even close, with the Busa pulling many bike lengths immediately and continuously. The salesman, who's a buddy of mine, said "I can't believe how fast that Hayabusa is!" This was after I had ridden the S and asked him "nice bike but, you aren't telling people they can outrun Hayabusas on these are you??" He smirked at me like I was an idiot and the run was on.
Both R and S models seemed to handle a bit twitchy in even moderate corners. And the servo assisted brakes, OMG. Initially you get seemingly no reaction, making you wonder why the brakes aren't working and then they clamp down hard, upsetting the bike. Not cool. Off idle fueling was delayed and twitchy as well on both the R and S. I'd prefer a Boxer cup variant without the servo brakes and such. They aren't that fast but they're so torquey that they're loads of fun. My best friend and riding partner has a Boxer Cup Replica. Very cool motorcycle.