I too have had data loss from BTRFS. Had a RAID-1 array where one of the drives started flaking out, sometimes it would disappear when rebooting the system. Unfortunately, before I could replace the drive, one time when booting my array had been corrupted and it was unrecoverable (or at least it was unrecoverable with my skill level). This wasn't a long time ago either, this was within the last 2-3 years. When I got the new drive and rebuilt the array, I used ZFS and it has been rock solid.