I just got a new 4.5 Domane and I gotta say its pretty sweet. I'm not great with all the numbers on the gearig but I now ride a hill that I rode in the largest gear I had in the rear on my old 1.1 trek road bike and with my new Domane I have 2 larger gears left to go to if needed.
I wish I could talk in techno talk but in my terms I am able to climb hills better and am in much more comfort on the entire ride with my new Domane.