Sadly it's pretty poor
Like Peter Jackson's King Kong, this film is more concerned with showing how clever it is at creating a period New York piece entirely in Britain. And technically the film is pretty cool (there's a wonderful CGI use of actual stock footage from the time in one scene).
Sadly the script is low rent, cliched and gets duller as the film progresses. Jude Law over-acts to a horrible degree (the director's fault for not reigning him in), and Colin Firth is just dull. Neither have any chemistry with one another on screen, which given the script is a disaster. The side plot with Wolfe's wife (Kidman) is just the pits, and would have been better reworked or removed.
Biggest mystery is why Law plays Wolfe as Dylan Thomas meets Rik Mayall. I guess the film-makers considered the real wolfe as too dull- in which case why make a film about this (very) obscure writer).
Shame really cos for the first 15 mins it seems as if the film is going to be quite good for this kind of thing. Then the short-comings become painfully obvious. Oh, and insisting that 1929+ setting means everything must look hyper-dreary was a very childish visual error.
If you like these types of story, you'll probably think this movie OKish, but it's a poor example of the genre.