I think the pacing of DK was far better than Begins as the whole origin thing slowed Begins down.
Free from that kind of baggage, there were very few lulls in the storytelling.

Joker, we never got, and never wanted an origin, which was great.
And Two-Faces origin was so ingrained into the plot, and strung out over the whole movie, that it was never a distraction.

I think one thing Dark Knight showed is that you can have a multitude of characters and plot points, without it becoming bogged down and half finished (see Spidey 3).

One of the things I was incredibly happy to see was the death of Rachel.
That was one character I hated in both films, and was glad to see the back of!

Snarf is shit. His death will be rejoiced!