Seriously, Apple need to start using openQA. Second 27" iMac in as many weeks is borked thanks to the latest OSX updated. Whilst on the phone with Apple Care going through the troubleshooting steps (again) the Fusion Drive decided to umount itself and not let me re-mount it. This all stemmed from applying the latest OSX update, that then disabled bluetooth and wouldn't let me re-enable it resulting in no IO devices working as Apple only ship BT keyboard & mouse. Thankfully I have a few old usb ones lying around.
I've only had one similar issue on openSUSE, and that was 100% down to me futzing with the kernel - thanks to zypper/BTRFS snapshots I recovered within minutes and was back working.
I've heard the likes of +Jon Masters
rave about Apple QA, but seriously in comparison to Google and pretty much any of the Linux vendors, they suck. I know +Markus Feilner
will bang on about boycotting Apple, but there are requirements and the iMac fulfilled all of them.
Unfortunately there are various proprietary apps needed by various members of the family, that preclude Linux from being an option. I've not found a comparable Windows machine, but if people have genuine recommendations I'm all ears!