Went with the family on opening day, after brunch and before dinner. A lot of discussion will center on the title character. As a fan of both the original stories and of Laurie King's Mary Russell novels, I like the original -- and am maybe a little biased against taking too many liberties with him. I really like the fact that parts of the literary character that aren't normally emphasized were brought to the screen (boxer; depressive brooder between cases; drug addict); but it was a bit frustrating that, in typical Hollywood style, each had to be exaggerated for greater effect (martial artist; essentially bipolar; poly-drug user).
Downey was fun to watch, as was Rachel McAdams -- glad to see Irene Adler resurrected from the original, a minor character with a lot of potential. The hardest part for Downey, I thought, was to portray Holmes as being simultaneously dissolute to the point of incoherence and superhuman in both mind and body... but that's how the character was written, and he managed to pull it off. Without giving away too much of the story, it was suspenseful enough to keep you going, with the usual Holmes device of slipping the clues in under your nose along the way. Enjoyable and worth watching -- thumbs up.