I have heard on Superbike Planet and a couple other inerviews that Yamaha insiders admit the cross plane engine is down on top end HP. They also claim it doesn't hit the high straightaway trap speeds the Duc, GSXR, or Aprilia do.
This due to the fact they have not figured out how tight they can turn it and it still live. I feel like as they put race miles on these engines and experiment a little more that we will see a higher output cross plane later this season.
That said it doesn't look like they are going to need any more top end for now...
