In the end, if I recall correctly, there's just not enough meat on this bone for it to stand up to its many challengers.
Though I haven't seen it since it was in theatres - now that the Bush "legacy" is completely established, I wouldn't mind re-evaluating it - I remember thinking that he exploited too many loose connections and popular opnions (not to mention sentimentality). Unfortunately, to make a point like the one he was trying to make in this film - which I still don't think I've quite identified - he needs to back it up with a little more substance... though if his point was simply a combination of "Bush is an idiot" and "The Iraq War sucks", well, he succeeded there, but that's not exactly something most people couldn't construe from the newspaper most mornings... as entertaining as the rest of his work, but not as intellectually engaging, which makes it sort of ironic that this garnered him the Palme d'Or. Then again, generalities about America would be more likely to appeal to people who don't live there.
I like Moore, but I always try to take him with a grain of salt... and for this over-emotional, even if reasonable - but not adequately substantiated in the film! - culmination of his anger with Bush, I had the sense that I might need a couple kilos.