I think tires are the main issue when considering gravel, but if you start talking about roots and rock gardens, then issues like bottom bracket drop and wheel base become important too.
Honestly though, if you are planning a tour with some sort of load, I don't think you will want to be doing too much mountain bike style riding.
My 1000 will handle 38mm tires no problem, which is fine for most gravel and dirt. I say if you can snag one, go for it.
