By sheer coincidence I read a few of the Sherlock Holmes stories just before this movie came out. I'm very glad I didn't see it in the theater because I think I would have been a little annoyed with the liberties that were taken. But as I have no memory for things I read I only had a vague discomfort about it and then got over the whole thing and enjoyed the movie.
The story sort of gave me the creeps (secret society practicing the dark arts), and also, was a little dull, and I have a hard time watching fighting sequences with all those realistic sound effects. I can close my eyes through the rough parts but I can still hear the bones snapping. Eek. But Sherlock Holmes is one of the best literary characters of all times and Robert Downey Jr. played him expertly. Well, for a pumped up action hero - which is a bit ridiculous - he played him expertly. I also think he would have done a great job with the traditional more cerebral/less punchy Holmes with the deerstalker cap. He got the essence of him - making him the smartest guy in the room and knowing it. Jude Law was surprisingly good as well. I say surprisingly because I'm always surprised when I like him in something. The mustache helped - as it always does.