Yes, the joker character is very good, with many ticks that shows him like a really crazy psychopath, but the Batman character, is a little too good, too righteous. He had more than one chance to finish the joker, but he can't bear to kill a maniac sociopath killer…
The action is quite incomprehensible, very close shots of dark figures moving very fast. Personally I like to see a good kick a little more clearly. Also most of the “impressive” stunts are not justified to accomplish anything. I got fond memories of the old 007 films when they use the skyhook though. What was also disappointing was the general lack of blood, I mean, it is a violent movie, everyone knows that, but the joker can cut somebody's face and you barely see a drop of blood.
The Two Faces character was good, never was my favorite character but in this movie was everything it needed to be.
The plot seems to lack a bit of consistence, the objective of the villain is never too clear, nor too big, and they are mostly small, localized and unconnected hits to Gotham, batman, or the mob.
Nevertheless, it was fun to watch, (yet not so very exiting) I liked Batman Begins a lot more, so If have to recommended it to a friend: Go see it, but don't expect too much.