I was down at Scooterville for some minor work on my xc500 today and took the chance to sit on the 700 they had on the floor. That is one beast of a scooter. About 100lbs heavier than the 500 and you do really notice that, hauling it upright off the side stand. Just like lots of other folks have reported, it feels more cramped than the xciting, but the thing that struck me as strange was that it shouldn't. Feet forward on this thing my 34" inseam legs were at the SAME angle and position as on my bike, (yeah, so sue me, as a martial arts instructor I'm used to being VERY aware of body position, probably almost as much so as a dancer) so why did it feel tighter and less relaxed than mine?
I finally figured it out. It was the seat. The 700 seat has a radius into the integral butt-rest, unlike the one on the 500 where the discrete piece of the butt-rest makes an angle with the relatively flat base of the seat. That radius pushes your ass forward, tilting your hips and making it take more forward pressure from your legs to secure you and make you sit IN the bike rather than be perched ON it.
The seat pans look almost identical. Perhaps the problems with the fit of the 700 would be fixed by simply mounting a seat from a 500?