I concur with your statement about Elfman's theme. It's not happy jolly, I always thought it fit the character, setting and style of that 80s batman style perfectly. And it's very energetic.
Zimmers new theme for the dark knight is a Zimmer thing, totally. I like some of his ideas and think they fit the movie in a way. Especially that idea for the joker is very interesting and I wouldn't have imagined that something like this would come from Hans Zimmer, so in a way, he really managed to impress me here. But his batman theme... well, a Zimmer thing, it could have been played in a movie about a presidential affair or another action flick. I associate it more with Hans Zimmer than I would associate it with batman, something that would never happen - at least for me - with Elfman's theme, which is batman.

Hope any of this makes sense.

Cheers
Flo