Adam Leventhal on APFS:
I’m not sure Apple absolutely had to replace HFS+, but likely they had passed an inflection point where continuing to maintain and evolve the 30+ year old software was more expensive than building something new. APFS is a product born of that assessment.
APFS will be an improvement at stability for Apple users of all kinds, on every device. There are some clear wins and some missed opportunities. Now that APFS has been shared with the world, the development team is probably listening.
Apple’s goal is to have everyone over to APFS in 18 months. That’s ambitious to say the least but if their adoption rates of iOS releases are anything to go by they’re good at getting people to move on.
Those dragging their heals will likely be the desktops.
Source: A ZFS developer’s analysis of the good and bad in Apple’s new APFS file system | Ars Technica