I saw it today and enjoyed it. It's been a long time since I saw the Broadway show and I haven't 'caught' the anniversary specials, except for the very ending. So, I'm avoiding comparing it to any stage production.
I thought the actors/actresses were cast well. Jackman, Hathaway and Barks were standouts for me. I shed a few tears during 2 scenes. Seyfried and 'Marius' were fine, but there singing wasn't my favorite - perhaps because they shared songs with Barks. I didn't mind Russell Crowe too much - I actually thought his singing suited the role, although I definitely wouldn't rush out to buy any recordings of his singing voice.
I do think that the movie got a little bogged down by all the singing - some of the conversations could've been done in normal speaking voice. Many of the classic musicals aren't done entirely in song. It kinda of reminded of Umbrellas of Cherbourg where every single word was done in song, even though it really wasn't necessary.
The backstories of each character was more fleshed out in the movie, which is something that can't be done as readily in a stage production.
As others have mentioned, the story is not your typical light and airy classic musical..... neither is Phantom of the Opera nor Miss Saigon nor Rent.