It would be cool to hear your impressions after the demo if you get the chance.
The demo was very cool. I was concerned I would be on a bike set up for a 150 lb guy, but they ask your weight and dial the bike in for your weight, so the suspension and tire pressure was right. They had several bikes to choose from, but most were very high end (lots of Carbon and nothing lower end than a Campy), which was disappointing as I really wanted to test ride a bike that I could actually afford.
I only got to test ride a 26" Stumpy FS S-Works (like I can afford an $8000 bike, but that's all they had in a medium). The geometry felt great, not much different from my Rockhopper. The suspension took a bit to get used to since I've only ever ridden a HT. I was very impressed at how the suspension absorbed bumps. I guess I was expecting a kind of bounciness, like hitting a bump in an old Buick or something, but instead the suspension just absorbed the bumps like they weren't there. The "brain" seemed to work well as I didn't notice any sag or bouncing on climbs. I did notice the brain cause a sort of catching before the suspension kicked in at times, which I've read complaints about. Didn't seem like a big deal, but for others who are used to a certain FS feel it might be. I think I'm changing my mind on the FS vs. HT decision. The FS made for a really smooth ride.