For a comic book movie, I though "The Dark Knight" was an 'A' effort. I had no trouble following the characters or the story. Not once did I think "Lets get on with it!!" or "Whoa, slow down, dammit!" Furthermore, the plot was engaging and remained so even after I saw it three time in the theater. Granted, there were plenty of comic-isms that would be in no way plausible in real life, but that's why it's a comic-book movie.
The one thing that did grate on me however was the raspy voice. I didn't mind it in "Batman Begins". I didn't mind it during the first half of "TDK", but somewhere around the point where Dent finally goes nuts Nolan decides to jack up the raspy voice effect by a factor of ten. Batman's dialog just starts overpowering everything else and it got damned annoying.