Slow pace in the most part of the movie.

just watch it!

It's entirely possible that sending the audience out feeling lousy was intentional

If you're interested in the topic at hand, you should just watch it and judge yourself because the reviews have gone very biased by people that didn't even watch it and just hate (or love) the creator. I liked it, it was well written, narrated, and directed and it was about a topic that interests me.