I hurried back to give a tiny report until the notes. By the end of the film I thought I'd been sitting there for two-and-a-half hours and it really seemed THAT long. In reality, sans credits, the film runs just shy of two hours. Part of it is inherent to the show itself. So, caveat first: I'm not that huge a fan of the show itself - I do love much of the score, but the show itself has not ever engaged me the way it has others. The movie is very well done, and happily does not have fast cutting and is nothing like Chicago in that regard. Certainly it's the director's best film visually, although in the last half I could have lived without the constant camera moves, which get more and more pointless as the film goes on. The score almost survives well with a couple of numbers cut along the way. The cast is very good. It makes no pretenses about being a musical, although you would not know that from the trailer. So, while that silly ploy may get people in the theater, I think many mainstream filmgoers will bolt from the constant singing - and for much of the score, it's not exactly "easy" music. They do lay on the background scoring with a trowel - it's huge. It was a pretty full house. The film got a smattering of laughs, but not one huge laugh where the audience laughed as one. At the end, a smattering of applause. Even though they lay on song buttons rather loudly, no song applause at all, which is good. And this WAS an industry audience.
Here's what I can tell you in advance: The musical theater nerds will be lined up to see it. They will cheer as the lights go down, just as they do in live theater, which I loathe. They will scream with laughter, they will applaud after numbers vociferously, even if they are the only ones in the audience doing so, they will week copious tears in the last twenty minutes. They will applaud every name in the credits. Mark my words. How this will fare with regular "folks" is something I can't predict. It really could go either way, but my instinct is that young non-theater people won't like the relentless singing. We shall see.
To sum up, I enjoyed it, didn't love it, enjoyed the cast and the presentation for the most part. As screen musicals go these days, it's fairly true to the show.