I also really enjoy Peter Howell's theme and incidental music. It instantly takes me back to being 11 and watching Who on Saturday afternoons. And for that reason, most of Davidson's stories have stuck with me just as long.
I like Davidson as well, but mainly his stories. I think his character lacked the presence and insight of almost every previous Doctor. He allways seemed to me to be a fumbling, awkward, asthmatic sort of graduate student who was unsure of himself.
The fouled regeration may have been an attempt by JNT to reset the character a bit, but in my opinion he should have developed the personality differently, but yet kept the character of a centuries old timelord. Companions are for the audience to identify with, not the Doctor, at least IMHO.