Re: Top end
I don't think it's a possibility.
It's a fact.
Whether it's noticeable would come down to how familiar you are with the bike and how you ride it. If you live at high altitude every bike is going to be similarly down on power so a 1000RR is still going to have an advantage over a 929. Measure the 929 at sea level though and it may well have more power than the 1000RR at 5000ft.
On the other hand, if you ride around without going over 6000rpm you'd likely never notice the reduced power.
"I won't forget that ride for a while. Maybe you're right. Living fast might be worth the final crash. Maybe that's the secret you fliers know." - Flight of the Intruder