I have. It was good if you're a fan. Mostly just exclusive home videos, artwork, and recorded diary entries from Kurt.
For a documentary on Kurt's death & Courtney's involvement, watch Kurt & Courtney.
Nirvana may be the only musical act on the planet which I like a lot and yet also think is overrated.
Soundgarden was first. PJ was better and more long term. STP was more stylish. AIC was more grungy and dark.
Nirvana were pioneers and that gateway into mainstream from some underground garage type setting. Music was great. But I dont think they were the end all be all of the genre.
And as youve stated before, that entire decade and genre was a golden era of music indeed.