I hear you, but the FS has been silently deployed to millions of iOS devices already, so I'd imagine it's pretty well tested for them to bet customer data on it

I hear you, but the FS has been silently deployed to millions of iOS devices already, so I'd imagine it's pretty well tested for them to bet customer data on it. I also haven't had any issues with APFS on 10.13 beta, but I haven't used it in any fancy way yet.