You'll get conflicting opinions on this one mate. Its all down to your riding style really. I know of people who prefer one or the other, so its hard to say if ones 'better' than the other. My mates got a 07 600rr and he loves it. He went on 07 R6's too and prefered the rr. I personally prefer the look of the rr over the r6 though, but cant comment on how either of them ride. What i do know is that my old K5 gixer 600 could pull a slight gap over his rr though, but im sure performance between the two is very minimal.