Weight, ease of maintenance (thumper, air cooled), and agile. The 800 is my compromise bike, capable everywhere, yet nothing great. Not being a wealthy guy I would be on the bike that presented the lowest cost per mile. Heck, I would have a silk tarp and tyvex ground cloth for shelter. My camp stove (
http://www.advrider.com/forums/showthread.php?t=431851) will be an alcohol burning beer can (on their way, I will be using these on my next trip), my biggest luxury will be a coffee pot, which also doubles as my cooking pot. My plate will serve many functions, frying pan, sand shovel, and for entertainment, Frisbee.
ADV riders of the current genre have very little in common with the ADV riders of old. I like comfort as well as the next guy, that is why I ride the F8, my tent is a Redverz and is so so nice. The winch? Insurance for a guy with a bad back, but it really is a convenience, I have rope and a couple of pulleys to setup a Z Drag.
We at the school broke it down this way, ADV Riders cross borders as minimalists, DS Riders do paved and unpaved, Dirt Riders ride dirt. It has been said that some %70 of the roads on the world are unpaved. I have a hard time wondering why so many confine themselves with the often overcrowded paved bits?