How comfortable a bike is depends on who is riding it, I can go 300 miles easy on my 07, while my friend can barely stand to ride it across town. The whole "the 09-10's have better low end" craze has more to do with gearing, as the US 09-10's come from factory with a 47T rear sprocket where as the 07-08's came with a 45T rear sprocket.
For keeping this within a certain tolerance these are both from akrapovic and I am assuming these where done on the same dyno. Now I have looked at several other stock dyno graphs for the 09-10 and 07-08 and the curves are all pretty damn close to each other. (if anyone has a base, as in stock form dyno graph for a 07-08, 09-10, let me know so I can add it)
Now I do agree with the whole resonance being applied to the back tire when leaned over and on the throttle, as one piston applying force to the crank at a time is going to have half the force of a flat plane crank that has two pistons applying force. But if we break the pulses applied to the tire into a measurable frequency and coincide that with the amount of friction the stock rear tire is capable of, assuming both tires have the same contact patch and added that the crossplane requires counterweights which adds weight to the crank which not only reduced the total piston acceleration, but helps to absorb these pulses which would create less of a pulsating power delivery from the tire to the ground. (taking the little rubber absorbers in the wheel out of the question)
Now though, I don't love or hate the 09-10's (I hate the ugly ass body though) but as suspension designs change and we can pretty much expect a large majority of what we currently know now about setups is going to change, I can honestly see the flat plane crank remaining dominant until they can get the weight out of the cranks.
This is all just my personal opinion here and I'm kinda drunk, so excuse me if I made a few mistakes.