7. Older Doctor = Homage To The Classic Series?
Since he does have the staying power, and he is older, the show is most likely going to change. I'm certain he can still do the "awful lot of running" that we're all used to, but Capaldi could bring about an homage to the classic series, bringing in more exposition and proper resolutions to episodes as opposed to some of the more recent "let's drag out the story and have a few laughs before tying it up in a messy bow in the last five minutes" plots we've been given. Capaldi would definitely have the power to foil his enemies with barbed words instead of ridiculous pseudo-science (Which is still fun, mind you). There's nothing wrong with a little humor, but I'd love to see Capaldi reach a darkness that Smith barely scratched at, even if it is just with subtle actions and harsh words. With his age, though, the writers are bound to focus more on his intellect than his physical prowess, which is just what the show needs.