Backpack for Europe

Alright.. after trying on a million different backpacks at REI, Anymountain and Big 5 and actually purchased two, I have decided that I'll settle on this . I'm a bit worried because it does look quite small, but a 2500 cubic Women's bag in REI was already so big, and this one is 2500 cubic unexpanded, 3000 cubic expanded. This one also has the best review and everyone reviewed seemed to be ...