Wow. A thread old enough to have a post by Dianna in it. The stock seat, as well as the stock riding position, including bars and pegs, are the main reason I have put 180,000 miles on 2 brand new Vulcan 750s. I also like the handling, power (for a v-twin) and looks. I am in the middle of replacing the stator and balancer dampers, along with a few other things, on my current VN750 rather than selling it and getting something else. There is simply nothing out there, new or used, that fits me and works as well for me as the Vulcan 750. And if any one thing stands out as being the most important, I would have to say it's the seat.
EDIT: Just read a post from someone who said he couldn't handle 30 minutes with the stock seat. I have done close to 24 hours with the stock seat several times. Tired, but no real pain. The stock seat, bars, and pegs provides a ride that is almost completely free of stress points.