Christopher Bird’s review published on Letterboxd :
It has an excellent score, outstanding cinematography, performances that are uniformly thoughtful and excellent, and that sense of purpose behind everything Tarantino does: whatever you might think of his individual choices (including his continuing obsession with using the N-word, and I do wonder how he's going to get around that with the Star Trek film he's supposedly making), QT is a director that you know is meticulous about all of his choices.
That doesn't necessarily mean his choices are good ones. What we have in THE HATEFUL EIGHT is a film that is too long, too indulgent, too in love with itself. It's three hours long and it should have been maybe two at the most. Maybe half of the extraneous run time is thirty minutes of flashback scene coming in the second half of the film, which details the killers' setup and just cuts the momentum of the film dead and isn't entertaining in the least: you're just sitting there, waiting for all these ancillary characters you already know to be dead to get killed. It's actively boring and completely unnecessary, and just because it's shot and scored brilliantly doesn't change that at all. Elsewhere throughout the film you keep getting the sense that Tarantino is too in love with the process of the characters' basic tasks (how much time does he spend on characters nailing the broken door shut?).
Basically, Tarantino has officially reached J.K. Rowling territory: he was better when there was someone with the clout who could tell him "no, too much." His own ambition is choking his movies to death.