It’s rather an odd duck. One set piece after another, usually entertaining but without much forward momentum. Also, it feels incredibly tailored to his personal obsessions – e.g., his pro-old Hollywood, anti-hippie nostalgia, and his wanting to re-create what a pool party at a Playboy mansion in the late 1960s might have been like – without entirely making the sale to the audience that we should share them at least for the film’s duration. (Cf. Hitchcock, who specialized in effectively transmitting his dark personal obsessions to the audience.)
Brad Pitt was very charismatic in the classic old Hollywood manner. DiCaprio, interestingly, was deliberately made far less so, although as an actor he obviously has similar chops.
The ending, not to issue undue spoilers to any few of you out there who might not know it yet (but who still plan to see the film), drew power from the (altered) historical event’s having such a huge cultural resonance, at least to anyone old enough to know and care about it. So there was a point at which the tension rises because one is thinking, my gawd, here it comes. But I still was left with a sense of a bunch of different things thrown together because they’re all stuff from 1969 that the director wanted to play with