First, when people talk about Moore playing fast and loose with the facts, I think they protest too much. He's a more subtle propogandist than people give him credit for. As an example I was looking for, and never saw, anywhere in the movie where he claimed the Saudis were allowed to leave while all the other planes were grounded. He indicated that they were allowed to leave starting 9/13, but didn't say 'everyone else was grounded.' They left at the first moment that air travel was beginning to resume. As it happens, the media is just now uncovering the fact that Saudis were allowed to fly when
everyone else was grounded.
Moore omits facts that don't support his worldview. Moore manipulates the audience with editing and juxtaposition. He presents circumstantial facts and points the audience at conclusions he's too coy to state baldly. His utter lack of respect for Bush and the current Administration may bother anyone who still feels the President deserves some a priori deference. He presents a whole lot of smoke, and precious little fire. But by any objective measure he's at least as truthful as the Bush Administration, their toadies and camp followers.
What the movie does, more than anything else, is to present with no lack of humor and humanity, exactly what it has felt like the past four years for folks like me to watch our country turn into a destructive jugggernaut ruled by ignorance, deceit, and arrogance. It doesn't even matter whether at the heart of the presidency there is a conspiracy to re-make the country into something ugly, cruel and power mad, or simply a bunch of blinded ideologues following their misguided convictions over a cliff. Something horrible has happened to the USA, and 9/11 is only a small fraction of it.
I don't expect, any more than Moore does, that my little rant is going to change anyone's mind. But I think it's important for everyone to critique their own beliefs now and again. If Moore raises some questions in people's minds about what's going on, he's doing his job.