Went to see this today. It was enjoyable, but I don't think it was a good as the first one. As I remember the first one had more detective stuff going on, where as this was just a few action sequences strung together.
Just like in Star Trek TNG (Data's Nemesis), I found the Moriarty character to be intriguing and I enjoyed every scene he was in. I was very impressed with the film, and I will probably need to rewatch it as it seemed to be easy to miss witty dialogue.