[mrpippy]

On that note, I am surprised that they added Fusion-awareness to APFS, rather than just putting APFS on top of CoreStorage.

It certainly is better to have the filesystem aware of the Fusion situation, but...measurably, significantly better? Would the experience have been significantly worse without it? 10.13 betas allowed APFS use on Fusion drives, presumably without any Fusion-awareness in the FS.

I'm surprised, but happy to see they did it.