1) First of all, a caveat. These two movies are not really comparable (even though both concern themselves with revenge, and both are about “civil wars”). Hateful Eight is a work by a major artist, though perhaps a bit off his best. Civil War is a corporate product, though a very enjoyable one.
2) They are mirror images in one way, though, which is that Hateful Eight is basically what happens when your movie has all villains and no heroes. Tarantino has said that it was inspired by some TV shows he saw as a kid when a team of villains would come into the heroes’ place and hold them hostage for an episode. I remember those episodes, too. But what, he thought, would happen if you removed the protagonists from that scenario and made it all villains? Well, this movie sort of answers that.
Civil War, on the other hand, deals with the fact that the Marvel movies have never come up with an interesting villain (other than Loki) by mostly pitting the heroes against each other. This is very different from the contrived “Thor vs. Iron Man!” fight in the first Avengers movie — this is based on an actual disagreement (with some amount of personal resentment, too).
There is a “villain” in the movie, but for once it doesn’t matter that he’s such a cipher (and it would have been an interesting move to eliminate him entirely — but that wouldn’t have served the corporate mandate that a superhero team broken into parts has to reunite in time for the next movie).
3) Hateful Eight seems sometimes like a showoff move by Tarantino — demonstrating that he can carry off a movie that runs three hours, is set in a confined space (admittedly a large, confined space), has a lot of talk but no action, and has no sympathetic characters. And he pulls it off, but (as was pointed out at Pages of Julia), it lacks the level of thrill of some of Tarantino’s other movies. I can remember camera moves in Inglourious Basterds that thrilled me, on a visceral level, more than anything here.
That being said, well worth seeing.
4) One thing that bothered me about Hateful Eight is that it is structured as a classic Agatha Christie type mystery (fixed group of suspects, cut off from the world — who is hiding secrets? who is the killer?) but it makes one mistake in terms of the form. The first time a character in the snowbound stagecoach lodge Minnie’s Haberdashery announces his conviction that one of the other guests is not what he seems, there’s no evidence for this. Now, he’s not the character who ends up serving the function of the detective, but still it could have been handled better (I could think of some pretty obvious “evidence” that he could have pointed to).
5) One thing that I figured out from watching these two movies is that “action” and “violence” (in movie terms) can have nothing to do with each other.
Civil War has action, but pretty much no violence. Lots of characters to action-y things — punching and leaping and zapping — but there’s no blood, and the deaths that do happen are almost all off screen. There are a few bruises, and one more serious injury.
Hateful Eight has no action, but it has a lot of violence. Guns are fired, blood appears in copious amounts, characters die (some quickly and some slowly), but there’s very little movement. The violence is mostly sudden and deliberate and brutal.
The difference, of course, is not an artistic choice — it’s the business mandate that superhero movies (except for oddities like Kick-Ass and Deadpool) have to achieve that PG-13 rating.
6) One thing that clarified Hateful Eight for me was this quote from the Telegraph (quoted on Wikipedia): “…a parlor-room epic, an entire nation in a single room.” That it kind of is.
7) Also, of course, I think it’s very cool that one reason Tarantino cast Jennifer Jason Leigh was because of her performance in eXistenZ.