Did a search on this and found a post release thread of only 3 posts. For some reason I thought there was more of a discussion on this film. Anyway, I went ahead and saw it again last night and it's still possibly one of my favorite documentaries (not to be confused with "best").
To this day, I'm still not sure it isn't an uncredited Christopher Guest movie. If Billy Mitchell were a fictional character made up by some screen writer, the notes that would come back would be "tone it down". He is simply one of the most entertaining villains I've ever seen in a movie and one of the funniest. Because for all his bravado and efforts to make himself a heel, he fails spectacularily at the most crucial moment in the film. Obviously spoilers ahead.....
Warning: Spoiler! (Click to show)
There's a scene late in the movie where Billy walks by Steve Weibe and mumbles "There are certain people I don't want to spend much time around" I couldn't continue the movie for a good minute I was laughing so hard.
The film really is a fascinating portrait of a group of men who essentially stopped growing up around the 5th grade and illuminate what a Man Child really looks like. It isn't pretty and it's funny as hell.