I agree, BTRFS has always been good to me as well and I use it day to day, however out of all the vague negativity in the comments below, this has real merit:

> ... raid5,6 had serious issues a while back - the write hole problem still exists for btrfs.

it does indeed. BTRFS should not be used on a RAID: https://btrfs.wiki.kernel.org/index.php/RAID56