@Natanox I've known too many people who thought btrfs was stable until it went foom at them. Maybe now it is stable enough, but people have thought that before. The main disadvantage with zfs is booting off it, which may or may not work depending on distro and setup.
I gave btrfs a number of chances and each time it fooled me (metadata running out of space, odd namespace corruption(??),...)
in principle I really like ZFS (having it also on my NAS), but even with ZFS-on-Linux kernel updates can be sometimes annoying
@RogerBW @Natanox