Theo Howe’s review published on Letterboxd:
In so many ways, I can sort of see what Once Upon a Time... in Hollywood was trying to do. I don't think Tarantino was making any great claims about how much better it was in the era of the bona fide, hypermasculine star. That said, he doesn't help himself. It quickly becomes evident that, while he doesn't hate women, he treats them with a lot less respect than men; any claims about this being a pastiche, a representation of how in this era, stardom was eternal for men and transient for women so long as they remained beautiful, are well meaning but made moot by Tarantino only ever vaguely waving his arm towards the women in this film.
And yet, when the film decides that actually it doesn't want to do anything grand, that it just wants to be a fun film about an aging actor, it is remarkably competent. On the whole, it looks beautiful, and having the scenes in the extended mode that they are in really creates the feeling that at the heart of it, everyone is bored of the whole thing following the honeymoon period, a period that Sharon Tate is still in. The scenes with Brad Pitt at the ranch, and with Rick acting as the heavy are genuinely superb, and scenes that would make a better advertisement for the film if it knew when to fucking stop.
We know that the ending is horrible. It's in dreadful taste as a concept, and even worse in practice. Recounting it to my friend yesterday, I still struggled to believe that it wasn't a terribly conceived joke. It's a nasty, brutish end to a film that did not look like it would have such a terrible denouement.
I have been overly negative in this review, and the rating may be more than it deserves. What I liked about the film (and there is a lot) seems boring and unimportant compared to its many indiscretions, so I focused on those. It still feels odd to say, but I would watch it again, but stopping 10 minutes before the end of the runtime.