Hello all!
Sorry to post yet another sizing thread, but this seems to be my best bet.
I am looking to purchase an '05 Gary Fisher X-Caliber and I'm torn between frame sizes. I'm just shy of 5'11" with an inseam of about 33.5". I cannot make up my mind as to whether to go with a 17.5"(M) or 19"(L) frame. I took a very brief testride on a 17.5" '03 model, and it seemed to feel alright with the seatpost most of the way out- better than the 17" Kona that I currently ride. I've also done my homework for the most part, and come to find out that Fisher has increased the standover on their hardtail 29ers by about an inch for each framesize. So as where I probably had 5 inches (give or take) of standover clearance on the medium '03, I would assume that i would have 4 or so inches on the '05 model. Bump that up to a large for the '05 model and thats about 3 inches of clearance. Maybe less if I'm mistaken on the clearance.
This is driving me crazy. I'm buying the bike through the store that I work at via Fisher's employee purchase program; In other words, if later on I decide that I've bought the wrong size, the option of exchanging sizes does not exist.
Let me also add that if I was purchasing a normal 26" wheeled bike, I think a large size frame would be my choice without much debate, since I have a fairly long inseam. With the 29ers, though, I don't know whether to stick with the framesize that I would on a regular wheeled bike, or to drop down one. I emailed Gary Fisher customer support, and they seemed like they didn't want to tell me the wrong thing, so instead they didn't really tell me much at all.
...maybe I'll get a unicycle instead. I think the geometry on them is a little easier to figure out.

Any input that you guys can throw my way would be greatly appreciated.