I used Arch Linux on my MacBook Pro 13” (2011) and it was almost perfect (one iGPU), some weird sleep issues, plus battery calibration issues: battery often went down to 7% within like 30 minutes, and then it takes a couple of hours to 0%. But if you happened to close it, it will either power off or hibernate (won’t recall). Then a couple of keys would stop working, and I’d just rsync my entire system to a newer (2014) retina MacBook Pro 13” (instead of fixing the keyboard, there’s no point in that). Perhaps, these laptops are very popular for Linux enthusiasts — I think 15” from 2015 is the best Linux laptop you can get for the money — but this laptop is just perfect! Everything works flawlessly, sleep, hibernation, screen, keyboard backlight… ah, I forgot about the web camera, doesn’t, but I never used it really, it’s crap anyway. The battery life is amazing, I’m getting like 8 hours of real work for the new battery, or even longer for very light work. So, I’d say it depends on the hardware quite a lot. Maybe I’m just very experienced now, but I won’t say I am.