I haven't tried either bike, but wanted to make a comment about the compact double vs. triple cranks. Is the triple crankset on the Trek 105, Ultegra, or Bontrager? What brand/model are the compact doubles on the Specialized? Do you know what cassette is in each of those bikes? Will you be doing a lot of touring or climbing with this bike?

Depending on the brand/model and weight of each set of cranks, you may be better off (save weight and get smoother shifting) by sticking with the compact double and using a 12-25 or 12-27 cassette.

~Cari