I just saw the film last night, and coincidentally MM on Jay Leno's "Tonight Show" later in the evening. Now, I thought it was a brilliantly edited and quite moving film -- this from someone who is very rarely moved at films. I didn't actually cry when I heard the poor woman's testimony who denied a life-saving operation to a patient, but it was the closest since "Born Free".
Anyways, I think it is a very effective film because it is so well edited. I personally think it's his magnum opus, and he's unlikely to top it. It is of course purely an argument to emotion and humanity (shades of Tony Benn there and in his interview on Leno), rather than anything fiscal. Well, it takes the time to debunk the conservative claptrap about how universal healthcare would mean the state with howitzers on every corner that Ronald Reagan narrated.
Tony Benn was brilliant, of course. He does rather seem to have influenced Moore, because Moore almost explicitly echoes Benn's statements in the film about a demoralized and ill and overworked population being easy to control -- stating his goal is to speak for those who are demoralized, etc.
Anyways, I highly recommend the film, even if you know in advance you are going to disagree with it. The film is very, very good, and Benn is worth catching too.
Now let the wrath of the free-market capitalists be upon me!
[edit] Oh by the way, there was applause at the end in the theatre, which is fairly rare for a film of any sort. That may, of course, have had to do with the content rather than the work.