Bugginess abounds more than ever in Apple's software, and I'd love for them to take a cycle off and just work on fit and finish and bugs rather than features. But to be fair, if you're judging against the experience of using Windows, well let's just say that's a low bar to beat.
As far as Linux desktops go, I think the way they run very solidly these days is phenomenal, but I don't think they solve everyday problems (things that watches and phones and other devices can do) as well as Apple. If you embrace Apple devices and services, you have a whole bunch of tools that work phenomenally together in smart ways. I don't think Linux really can match that whole package anytime soon.