In reply to what are the differences between "touring" and "adventure", I would answer that while all bicycle travel is an adventure, I believe what Trek, Salsa and Co-Motion (among others) have in mind is primarily "off-pavement" or "gravel-grinding". Adventure-themed bikes have heavier frames, wider tires, and more MTB-like gearing than touring standards, but also have the drop bars, long wheel-base and frame geometry for long-distance travel. In Europe they have called them "trekking" bikes for years. The Co-Motion Pangea and Divide and the original pre-2010 Novara Safari were the first American bikes to enter this niche of the market, followed by the Fargo from Salsa.
I see that for 2015, Novara has brought back the disk brakes and 1.9 inch (48mm) x 700 tires on the Safari, making it a new (or re-new) entry in the adventure bike niche, and although it is now just over $1000, it is still half the price of the Trek 920 or Salsa Fargo. BTW, it still retains the signature "butterfly" handlebars, too. Clearly a bike to consider if you are looking for an-entry level bike for "adventure".
I like, actually love, that the 920 has SRAM gearing. Although I have bikes with Shimano and SRAM, and one has a mix of both, I have always been a SRAM guy, but it is a matter of personal preference. I am going to wait until one shows up at a nearby Penn Cycle to make a more defined judgment, but the Trek 920 still tops my list for the bike to take the place of my venerable '06 Bianchi Volpe.
My big trip this year will be on my Cogburn CB4 fat-bike, across the western Adirondacks, where I grew up and where I was a licensed guide in the 1980s before we moved to MN.
Ride safe,
Hans