I'm not expecting a unibody design and flawless color gamut or anything. Even basic OS functionality like sleep/wake, (dis)connecting external displays, trackpad responsiveness, etc., is vastly inferior on Linux laptops.

Well, depends how well you know Linux. My old Asus Zenbook has been a great servant, running the same Arch installation since I bought the laptop. Superb fonts, suspend/hibernate etc works, Intel and Nvidia GPUs both work, WiFi connects automatically and I can manage the networks from Roxterm, I still have a pretty good battery life and nothing beats my Xmonad setup.

And yes, the build quality doesn't match Apple. But actually I really don't care. Over three years of daily usage already and I can't really complain. Next thing I'm checking the Razer, Dell and Lenovo selection, but it seems I just don't need an update yet.

I'm a developer, I do hard stuff for work. Setting up a Linux distro is peanuts compared to the issues I face daily. And no, OSX is far from a usable operation system for my usage.