Yes. The intelligent multi-device-type feature is a huge improvement for any workload that needs more space than what an SSD can affordably provide, even moreso with the reliability of eg RAID1.
Before that I had to use BTRFS (RAID1) on bcache (not fs) devices, but half of the cache space was being wasted on the redundant copies because the two systems operate independently.
What's wrong with XMPP? I've been using it for many years, it's by far been the greatest experience and it has OMEMO encryption.