Lot of people are rating it a 1 star for the sole purpose of hating on Kayne (current political views or life style) rather than ranking the documentary itself. This documentary is one of the best I have seen in ages. Instead of telling you about his life, it shows you and takes you on an emotional adventure with his group where you experience his dedication, his love for rapping and his mum.
Personally if you are deciding to watch it, I say go for it you won’t regret it.