I must admit that I hate Aprilia for introducing the 660 twin at this time. As usual, it is cutting edge gorgeous, and has a torque plateau rather than a curve.
In essence, the two front cylinders from the RSV4, but expanded from 535cc to 660cc, 270º crank w/counterbalancer, with a much lower redline. 10.5K peak hp and revs stop at 11K. Only teasers so far, but what a teaser. Bars above the triples, pegs slightly lower. Maybe 400lb all up. An absolute HonKawaYamaSuz killer. The AMA is probably writing rules to limit it as we speak. Price? Yeahhhhh...