APFS is slated for a 2017 release, yet development started as recently as 2014. By comparison, development on Btrfs started all the way back in 2007, yet many still consider it to be unsuitable for widespread deployment, particularly in mission-critical settings.
If Apple can actually pull off this turnover so quickly, does that suggest the complaints about Apple's declining software engineering quality were overblown?
Edit: Ted T'so in this talk(1) (at the 8 min mark) discusses the taskforce that birthed Ext4 and Btrfs and its estimate (based on Sun's experience with ZFS, Digital's with AdvFS) of 5-7 years at a minimum for a new file system to be enterprise ready--an estimate which definitely proved optimistic with regard to Btrfs. Will APFS be different?