Very interesting film, quite complex, fascinating concept. I found myself however doubting the motivation of the characters, were they really getting enough to take such risks? Obviously visually stunning, but I found Dicaprio particularly distracting with his acting. He's just NOT a leading man. Period.
But probably a bit too sophisticated for American audiences. Downey and Law are a terrific tandem as Holmes and Watson, the villian is good, good plot and pacing. The only problem is much of the humor went over the heads of the average American movie-going audience. My only problem with the cast was the beautiful Rachel McAdams, who is lovely to look at but her 'American' accent was a distraction throughout. The ending set up for an obvious sequel, and let's hope this movie does enough business to warrant a second adventure.