I’ve been using btrfs for about two years now on my primary machine. Single disk, btrfs-on-luks, on a 970 evo plus. I have never had any stability issues, and as far as I can tell performance is excellent.

I’m not taking any chances, though, seeing as it is “unstable” – I’ve got snapshots and local and remote backups set up and working flawlessly. It’s sooo awesome to be able to pluck older versions of any file on my system whenever I want, and it’s saved me numerous times.

I haven’t tried zfs but I really have no need to. Btrfs does the job for me.