Sly left me with the same ambivalent feelings as the documentary about his muscular counterpart: Arnold.
I liked getting to know more about Stallone's childhood and early years, although I think his X-rated career start should at least have been mentioned somewhere, without footage of course. 😅
What I disliked was comparable to what I disliked about Schwarzenegger's story: it was too (self-)congratulatory, and the narcissistic side of their personalities became emphasized.
I would also have liked to hear more about First Blood, which I consider to be one of his best films.