MacOS 10.13 is even worse. When I tried to install update, installer crashed in the middle of installation (seems that it's common problem[1]). After I managed to install it, I found out that it's extremelly slow. Time machine causes complete freeze for few seconds when starting each backup. It's literally Vista. Most issues were fixed in 10.13.1 (which installed only from second try too, each taking 2-3 hours), but, for example, Finder still has random line height that clips file icons and randomly chooses display mode for each directory.
And it's supposed to "just work" so there's no way to diagnose problems.