Awful
Saw it on Saturday with a film group, and the general opinion was not positive.
It starts strongly, the visual style is striking, I particularly dig the 70s style, and there are some great scenes. However, it needs a severe editing - it drags, changes pace suddenly for no apparent reason, jarringly includes a music video, and is inconsistent about what is happening outside the high rise.
I'm sure that parts of it are highlighting various parts of society, social hierarchy, and social climbing. I don't care : it's not a good film. Worth watching once, but not more than that. It could be halved in length and improve over its current state.
Watch The Lobster instead, it's excellent.