The 520's a 1in steerer (or my 204 is, trek sells it with a shim to use 1 1/8 stems) and I doubt the multitrack is (though i doubt this is a huge advanatge for tourer). Check brazeons. Is the frame built in waterloo? Check weight, the 520 may be heavier (build stronger) or lighter. Check weld quality, the welds on my 520 are better than I've seen on most treks (not as cleans as the meticulous ones on my titus, but then they weld TI for a living).