I mostly bypassed !ownCloud v7. Originally installed v5, upgrade to v6 was reasonably OK, and v6 seemed stable and trustworthy. I don't remember much about v7, but there were a couple of instances where I newly installed synch with v8 where the (empty) server decided it was authoritative and the synch client dutifully emptied the folders I wanted to have synched. Maybe I'll investigate # that someone mentioned yesterday. https://cozy.io/en/