OK, let's investigate and have play with 3-node cluster, plus a monitoring node. Documentation is here.
CephFS is officially production-ready.
SES 4 still based on 10.x.x Ceph core. Not actual "Kraken" (11.x.x), which claims the stress-test stability for BlueStore 'engine' (detailed presentation is here).
The Calamary management project looks dead, as it stuck with 2014.7 version of SALT, which is completely outdated. The OpenATTIC package came instead. Installs easily, operates fine, looks nice - great choice, SUSE! Hope, it will last for long time.