On the Power Delivery Bandwagon
Give me a second to climb on.
I assume you're talking about new bikes.
None of the 600cc SS bikes have a lot of low and mid-range response, but the R6 is the worst. The thing is nearly dead until 10,000 RPM. This is really undesireable for street riding. You'll have to ride around with the engine screaming all the time to get any reasonable drive.
It does sound really good, though.
The GSX-R seems like a much better overall package for street riding and is a bit cheaper.
Why haven't you considered a new R6S? It's more street-biased and will get around a track just fine, probably within a few tenths of a sencond of the new R6 with equal riders. (Actually, maybe faster in the hands of most riders since the R6 is reportedly pretty tricky to ride at a 10/10ths pace.)