I'm a fan of the stage show and felt a bit nervous going in to see the film. I wondered if I'd leave the cinema thinking "why didn't they just leave it alone?" But, I LOVED it!
It is though, an entirely different medium. I think some of the singing was fairly muted, and by that I mean, the very OTT delivery for stage, made necessary by the fact that the audience is some distance way, would have been too too much, up close on camera, in a cinema.
I thought it an excellent cast. Eddie Redmayne and Anne Hathaway being closest (for me) to standout good singers. Russell Crowe (and the man is HOT! No dispute there) was IMO oddly cast, in the Javert role. But, he was being a screen actor, "doing a musical" and he portrayed the essence of the man's "being", his lifelong cause, to find Jean Valjean, really really well. The voice? Not so good.
My biggest disappointment was Sacha Baron Cohen. Ternadier is a weasely little man. Sacha's accent was all over the place and he just wasn't "him", for me.
Overall, I thought it fabulous.