Not OP, and I've already mentioned this a few times here on HN, but any OS that has two separate menus to configure mice and trackpads, and has two toggles for the scroll direction of each, which modify the same setting and toggle each other one way or the other is just bad. That's a stupid limitation with terrible UX.

Then you can add the utter undebuggability of the OS, the total lack of feedback on anything, magic buttons appearing only if you've filled all prerequisites, thus giving you no way of knowing what is missing, etc. etc. etc. I have no idea where this cult of Apple's UX comes from, it's just not great.