I have never attended a performance of the stage show Les Misérables so I have no comparison to share in that respect. I am also not an avid theatergoer, so in a way I will have a completely unprejudiced opinion.
Les Misérables is set during the French Revolution around the early 1800s. Jean Valjean (Hugh Jackman) is a recently paroled convict, overseen by the rigid officer, Javert (Russell Crowe). Valjean breaks parole and after many misfortunes seeks refuge with a priest at a church. Still stuck in his criminal ways, he steals the church's silver but is soon apprehended by authorities. When brought back to the church to be punished the priest instead denies the accusations towards Valjean and offers him more silver. Valjean, shamed by his actions and moved by the priest's kindness, vows to be an honest man. He thereupon follows the moral path, helping those in need, and adopting an orphaned girl named, Cosette (Isabelle Allen as young Cosette and Amanda Seyfried as older Cosette). Javert, the unyielding officer still on the hunt for Valjean, crosses paths with him again and again; a decades long cat and mouse game. Meanwhile, the French Revolution is being waged and the gap between the bourgeoisie and the poor is growing larger.
I find that cinema has gotten to a point where visual effects, costumes, acting and music has elevated the "movie musical" to a level where it is no longer a contrived, whimsical film adaptation but a work of art. Tom Hooper spared no expense with sumptuous visuals, makeup and costumes to create a feast of unimaginable beauty, yet also highlighting the squalid poverty that existed at the time. The streets were filthy with rubbish and waste, the people were afflicted with disfigurement and dental disease, and clothes were ripped and greasy. Anne Hathaway's fleeting character, Fantine, looked starved and full of hopelessness. The movie had a sense of realism I have not witnessed before in a musical.
The music itself was expertly executed. I have read that the singing was recorded onset, instead of in a studio beforehand and lip-synced on camera. This achieved a much more emotive and raw feel to the singing, and it evidently meant the actors could "act sing" as opposed to concentrating on getting the lip-syncing timed right. Apparently, (this I'm not entirely sure is true) the actors wore throat microphones to record, which had to be digitally erased in post-editing frame by frame. Also, the actors wore discrete earpieces so they could sing along with an off-set piano accompaniment. This allowed for more natural singing where the actor and pianist could adjust musical timing as they shot scenes.
The singing itself was good overall. I have to say though that both Russell Crowe and Hugh Jackman were a tad weak, Crowe especially. They weren't singing out of key but they didn't seem to be singing any form of melody at all. It was like they were speaking but singing instead. Anne Hathaway's highlight scene was a beyond breathtaking performance. She deserves the Oscar. The other characters in the film sang well. I particularly liked Amanda Seyfried and Samantha Barks.
Despite Crowe and Jackman's weakness with singing, they were an undeniably good choice when it came to acting. Anne Hathaway's acting has become a commanding force and this film clearly displayed her talent. Sacha Baron Cohen and Helena Bonham Carter delightfully added much needed comic relief to an otherwise mournfully sad story. The other supporting cast were great, some from the actual stage show, some completely unknown.
So in conclusion I enjoyed the film immensely. I loved that the actors sang on set bringing forth a plethora of emotion on screen. I was in tears by the end and that is a rare event. The music was perfectly recorded and arranged. The set design, visual effects, sound design, camera work, cinematography and costume design were all of the highest possible standard. Amazing production. I'd give it an 8 out of 10.