I was very skeptical of this movie when I heard about it being made.  That is because I am a BIG fan of the musical and I feel like very few movie versions of musicals work out. I find film versions of musicals often feel strange or awkward.  Usually it is just a facsimile of the stage musical with better effects and less engagement   It is often cheesy, choppy or campy.  I imagine this is because when you go to a musical there is a certain amount of suspended disbelief.  Basically, when you go to the theater you are “buying in” to letting the music be part of the production.  In a movie it’s not quite the same.  But somehow this movie had great “feel”.  I’m not sure how else to say it.  Whatever some other film musicals have that puts me off, this one did not.  It had a “real” feeling and was engaging.  Rather than being a facsimile of the stage musical, it was more like a movie that used the same music.  It had the epic quality of a big film, but also had the emotional power of a musical.
This seems to be the direct result of the innovative way they made this film.  I can’t say enough what a great job the director, producers and actors did in putting this together.  The singing in this film could never compare with the Broadway studio recordings, so it went a different direction.  Rather than record the singing in a studio before production and then having the actors lip sync for filming, they recorded the vocals live while filming.  And then the score was added later as the orchestra played along to the actor’s vocals.  The process sounds incredibly difficult, but they pulled it off.  This allowed for the actors to act while performing their songs, and it created some powerful moments.  Anne Hathaway and Hugh Jackman thrived in this environment delivered some very moving scenes.  Their goal was to capture some of the power of a “live” performance and I think it was a success.
The biggest criticism I heard of the movie once it was out was that Russel Crowe was bad.  So I was expecting him to be awful (like Pierce Brosnan in Mama Mia awful).  I don’t think that criticism is fair.  Crowe was not nearly as good a singer as Hugh Jackman or Anne Hataway, but he wasn’t awful.  His singing was adequate and his acting presence brought a nice gravity to the film.  I had no problem with him in the film.
In summary, I couldn’t more highly recommend this movie.  If you love the musical like I do, I think you will appreciate how well this movie uses the source material but creates something different.  If you haven’t seen the musical, the movie will give you a similar experience of the amazing story and power of the musical.  It might inspire you to see the stage version (which I would also highly recommend).  If you dislike the musical, you might appreciate the realness that the movie brings compared to the stage version.  If you dislike the musical and the movie, you might be dead inside.
I have gone back and forth on my grade a few times, but when I factor in the degree of difficulty it is clear that this movie is “Amazing”.  I will be buying the Blu-Ray soon to show this to my kids in a few years.  I think this movie will both change how film musicals are made and open the door for other big projects.