Here's what I wrote after seeing it last night:

If you liked the style, cast and storytelling of Guy Ritchie's first adventure of the classic detective, chances are the second film will satisfy you too. Downey Jr. and Law still shoot their mouths at each other like guns, which is always fun to witness. Speaking of guns, there is more action here and the tone is overall a tad darker and more violent without abandoning the humor.
But, like in the first, the highlights of the film are still the scenes in which we see Holmes combine his observations, those are both visually fun and cleverly presented. Ritchie simply enjoys to not just firing a cannon but showing us every detail of it from the trigger to the final impact, in close ups, slow-mos and with plenty of visual effects.
The film is not flawless by any means, but the somewhat straighter story, compared to the first film, makes it compelling to watch. Jared Harris is an excellent villain, his Moriarty feels like a genius equal to Holmes, even if his ultimate goal is a bit shallow. Their rivalry on par with each other makes for a very exciting finale, the solution of which is so brilliantly delivered that I am tempted to say the film tops its predecessor, even if just slightly.
After a lot of noisy shoot-outs it's also refreshing to see the showdown celebrate the human cleverness, not the ability to fight. Spectacular entertainment that should please all fans of the first.

7.5 out of 10 urban camouflage costumes.