Ive toured the Oregon/California coast on a crosscheck. I now own a Long Haul Trucker (700c)
The Crosscheck was more "fun" to ride, it had a sharper geometry, but would wiggle a lot at speed with a load. The LHT is like a Caddie, just let it go, its smooth and straight.
I prefer 700 wheels because they feel much smoother to me and the bike in general feels like it moves with less effort. Ive also recently moved to a 29er mountain bike, which is also 700c wheels. I feel a lot of the arguments for 26 are situational, i.e. yes you might be able to find more parts around the world, but honestly, how many of us are touring Mongolia?
I also find it MUCH easier to find legit tires for 700c. All the road tires I can find for 26 are usually some heavy crap for riding to work. And also too wide.
Another FYI, my girlfriend and I are touring Europe for 8 weeks next summer, and I am riding my 700c LHT and I am building her (5'6") a Crosscheck with a LHT fork.