It a very similar riding position, HP4 has faster acceleration, doesn't wallow in corners or front end dive when braking hard -as you`d expect with electronic suspension, the Brembo brakes are just fantastic, traction automatically kicks in and you only know that because the traction light flickers on, the quick shifter is so smooth ( I did fit a power commander and quick shifter to my 11 plate R1) but the HP4 one is so much smoother, all in all the HP4 is Awesome, the only thing it doesn't have over the cross plane R1 is the sound but hey, I can live with that. Just need to find a Double Bubble screen for it now, any advice from any one? the US site raves about the Fabbri ? screen, any one fitted one?