Daniel Henry Silver’s review published on Letterboxd:
Montage of Heck is not the first film to explore the life of Kurt Cobain. It's perhaps the third major documentary, following the Nick Broomfield directed, Kurt & Courtney, in 1998 and the abstract 2006 film About a Son. Yet surprisingly, Montage of Heck is only the first that tries to paint a full portrait of Cobain himself. Kurt & Courtney had Nick Broomfield too concerned with picking away at media clippings, concerning the relationship between Cobain and Love. And About a Son is far too concerned with its own image to say or do anything relevant. (The entire film is a collection of establishing shots from the areas of Cobain's life, with disordered interview segments with him played over it.) Of course, the reason for the fuller picture of Montage of Heck was that for the first time, its director Brett Morgan was given the full support of the Cobain family.
Since his death 21 years ago, Kurt Cobain's legacy has grown immensely from what once was something romantic and honourable to the commercial farce it is now. T-shirts, tattoos, iPhone cases, shoelaces, toilet paper etc. It's all there. There's even a T-shirt with his suicide note printed on it. His life and death have been romanticised so ironically, considering how he always responded to fame and admiration during his life. And the simple fact that another documentary now exists could be a further extension of his commercialisation. However, I think instead that this is finally a balanced, unassuming piece about a fascinating human being.
Montage of Heck does not have an agenda. If it did, Cobain might have been portrayed as the beyond-human entity that he is in About a Son. Instead, we see it embrace the less heady days of his life (and from what the film suggests, comprised more days than not). It's a realistic definition of his character, utilising a blend of the mesmerising and the ordinary stories throughout his life. So, anytime the audience feels a sense of affinity to Cobain, it's so clearly a genuine emotion. We feel that emotion particularly in the scenes of Nirvana live & recording sessions; and in the never before seen video clippings of Cobain showing a delightfully hilarious sense of humour. His Chris Cornell impression and mocking of Nirvana's critics were a joy to watch. Yet those video clippings also, however briefly, gave some light to the extent of his heroin addiction in one very uncomfortable scene of himself and Love. The juxtaposition between the good and the bad times allows what feels like an honest image of his character, instead of Brett Morgan manipulating the structure to conform to his own image of Cobain (or to a preconceived notion of what he wanted his film to look like).
Nevertheless, I can't rid the idea that film doesn't need to exist. One thing that I think it hopes to achieve is to condition a more respectful attitude towards his legacy. Though I cant see that happening at all. If a circulation of Nirvana and Kurt Cobain merchandise has been in any sort of decline recently, this film will only serve to turn that around. His attitude to life and fame were unique, in how much he cherished them and relied on them in his short time but also battled with an inner resentment for those things. It was an outlook on things that speaks to many people and always will in some way.