Or only slightly, since hour-long slots in the US tend to have 44 minutes of program time.

Actually, my biggest problem with the new Doctor Who is the length of the stories. It used to be that you got four or six 25-minute episodes making up a story, which is 100 or 150 minutes of story (minus a little for recaps and credit sequences), whereas now you get one or two 45-minute episode stories, so 45 or 90 minutes of story. As such, they almost always end up feeling rushed and truncated to me.