The reality is that, while BTRFS feature list is impressive, ZFS is second to none here. Moreover, ZFS is _way_ faster.
The real problem is what while BTRFS has good features, its incredible slowness with rewrite/append heavy scenarios make it almost irrilevant in the enterprise space (unless you plan to use it for something as a fileserver, with lots of small files to manage).
Surprisingly, that don't stop some companies (as Netgear) to produce BTRFS-based NAS appliance and to sell them as "virtualization-ready". I can only imagine their slowness in VM handling...
