I blew by a GSX-R1000 at deals gap on my stockish 2000 M2 Cyclone. Of course, the guy with me blew by me, and he was on a Honda XR-650 (single cylinder air cooled dual sport, maybe 40 RWHP on a good day).
It's the rider. (and the one on the aforementioned GSXR-1000 had no business on that bike, but at least he was being safe). Right behind rider skills is willingness to take unacceptable risks. Behind that is probably how much money you are willing to spend on rubber. Behind *that* is probably when actual engine comes into play.
Of course drag races are a different story... but a really good drag bike will have to be lowered and stretched and cammed to the moon to get the really good times, which would make it dull in the twisties. If drag race times are your quality criteria, then you consider a VMax and a VRod a sportbike, right?
Peak horsepower is a lousy metric for bike performance unless you want to be constantly shifting. It's the area under the full horsepower curve that makes for a good street bike, and what the curve looks like at the RPM's where you actually like to ride.
I have not seen the XB12 dyno charts yet, but with that new exhaust setup I think they will be fantastic... decent power everywhere, and it will probably pull hard right up through 120.
Just personal opinion, but I don't understand why anyone is riding on the street at speeds over 90 in the first place, much less running competitively at that speed. Too many safety unknowns, too many cops waiting to impound bikes, too much money to be spent on insurance after picking up that kind of ticket...
I just don't see it as a "sustainable" mode of motorcycling, and am Glad Buell is not selling out the 0-90 performance to get only marginally better top end. This approach is not for everyone, but it makes sense for me. I love the fact that I can take my Cyclone out on superslab and have a comfortable, stable, and smooth ride for as long as I want, then dive into whatever twisties I can find and choose whatever line I want. I shift if I want too, not because I have too.
What was it Erik Buell said in an interview?... something along the lines of "we build a bike for serious riders, not something for some adolescent to use scare the crap out of themselves once a year".
It probably comes down to "do you want a bike built for the track and made street legal", or "do you want a bike built for the street that can be built up for the track".
Track bikes can get away with more unsprung weight (even the worst tracks are far better then any street you will ride on), hotter cams (which give mondo top end but lousy bottom and middle) and a high power per cc ratio (which is a great advantage within your race class, but is a stupid limitation to burden yourself with on the street). They have more expensive and monotonous plastic thats always in the way (better aerodynamics gives better terminal velocities when into the triple digits).
Picture something like the FZ1, but instead of making it a "cheap R1", what if Yamaha had kept premium components, but designed them for the road instead of the track. They could have played with the wheelbase (it does not need to be stable at 170mph), removed a front rotor (lower unsprung weight so you can brake faster on crappy roads, and one big rotor is enough when you are not going from 120 - 25 - 100 - 30 - 120 - 40 every 1 minute 73 seconds). Kept the premium R1 suspension but built in a little extra travel... etc. Yamaha did get the seating position and the engine cams right. Suzuki came pretty close with the VStrom as well, but they annoyingly keep wanting to build "another TL1000", and keep t he wheelbase too long.
And the Buells "sound right"
IMHO

Really. I understand why other people like the race replicas, and even why peple like Harleys and VMax's. I am just explaining why the Buells work so well for me.