Voted XRR but I'm kinda torn between the FZR and it as hardest. Have a decent amount of very competitive experience with both now, and they both have their ups and downs. The FZR can be hard as hell to enter some corners and manage over a race distance vs. the XRR, but at the same time it just eats curbs for breakfast/lunch/dinner and has very good throttle response. The XRR on the other hand handles absolutely beautifully when it's setup perfectly and can be easy as pie if the gearing's right for the corner, but then you basically can't be cornering at all when you curb hop and the throttle requires much more attention on most corners. (Spin up the turbo, turbo spun up, drop throttle, play with throttle, full throttle again, etc. all within the space of a couple seconds.)