Well. I haven't seen it, but I can tell you about the general reaction it's getting at my theater:
Most people love it. In less than a week, I've had repeat viewers (one person was seeing it for a third time). When it's over, people applaud in the theater (though it isn't a very rousing or sustained applause like The King's Speech or The Intouchables received).
A few people have no idea that it is a musical and walk out because "it's not their kind of thing."
And there is also a small group of people who can't help but compare the movie to the various stage versions they've seen and feel disappointed because the movie version isn't as good as the version they imagined it would be.
The latter two groups make up a very small minority.
Oh, and about 90 minutes into the movie, it becomes bathroom break city.