Everything else being equal, a shorter wheelbase bike will corner far better than a longer wheelbase one. Nothing I have ridden is as quick down our canyon roads than my wife's DR 200. Up the roads, not so fast, but it's still a blast.
A 250 or so supermoto probably would be faster, but I haven't ridden one.
I have seen a 250 road racer almost keep up with modern liter race bikes, he would lose a 1/8 mile or so on the longest straight, but would almost catch back up after all of the corners. These were professional racers on top notch bikes. Overall he was losing maybe 1/8 second per lap or less. Watching him zip through the turns so much faster than the big bikes was very impressive, passing them left and right, inside and outside.