Generally, I'd say the tone is more fun and off the wall, but there's a lot of pathos. I'm okay with that. They're spenind more time on how the Doctor's losses have affected him, which isn't a bad thing....

While his mind is centuries old, his body varies in age. I can see that making a difference. You know, it occurs to me that I never thought of Dr. Who as a children's show. One with special effects that were about as good as that, but not a children's show, specifically.