I'm using it for a bunch of servers in a office lab. Not production. What is always failed to be mentioned, like in your statement above is that BTRFS RAID5/6 has a write hole problem just like all other software RAID5s out there like mdadm RAID5, and only ZFS has it sorted. So if you're using mdadm RAID5/6 it is not stable for production. As already stated previously the conversation belongs in a different thread, best not here to have these flame-fanboy wars.