So I went ahead and watched both Apocalypse and Dark Phoenix last night.
Apocalypse wasn't good, but it was entertaining. Dark Phoenix was a giant pile of shit.
The former film didn't take itself too seriously, and there were a lot of hilariously ridiculous deaths, plus some fun scenes like when Quicksilver saves everyone from the mansion blowing up or when Wolverine slashes up a bunch of jerks. They definitely force the issue with Mystique way too much because Jennifer Lawrence is by far the most famous person in the movie. Mystique is not that important of a character, and she's not even useful in a lot of situations. If you're going to put her in the forefront, design the story in a way that allows her to actually utilize her powers. Also, you can tell that Lawrence is over being painted blue, because she spends like five minutes of the movie in makeup and the rest as Jennifer Lawrence with 80's hair. Apocalypse looks dumb as hell, but he's enjoyable enough as a villain. Magneto kills, conservatively, a billion people and it seems like everyone was kind of just cool with it. Mostly, the movie works because it's bad in a dumb, fun way.
Dark Phoenix, though. Oof. It's not fun at all. It's difficult to tell this story with Sophie Turner, because she's not a great actress and has utterly failed to make me care about her character. Honestly, it's hard to care about most of these characters, and that's what makes trying to tell such a downer of a story fail where Apocalypse sort of worked. You don't really care about most of the characters in Apocalypse either, but the story is so over the top insane and the spectacle so grand that it doesn't matter. Here, it's all about saving Jean Grey, a character who kind of sucks. The two most enjoyable characters are Quicksilver and Nightcrawler. Quicksilver doesn't really get anything to do and Nightcrawler is primarily used as a plot device. So yeah, bad movie is bad.
Also, Apocalypse has the single greatest moment yet seen in any X-Men film: