I agree with Richard Bridge. The earlier incarnations of Dr. Who were level-headed, thoughtful, relying on brains rather than brawn (read military might) to solve problems.
They were ethicists of sorts given to reflective yet creative solutions.

The new Doctor has too many temper tantrums to suit me. (Needs a diaper change?)

Karen Gillan suggests to me a Scottish Valley Girl.

I think that Billie Piper and Catherine Tate added dimensions to their roles.

Have to say though that my fave was Lalla Ward.