From my favorite movies..

Go in cold, and you're likely to emerge with your blood boiling. This has to be seen to be believed.

It’s not bad or unwatchable but despite the amplitude of the spectacle, the end result is underwhelming.

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.