I have been running OwnCloud/Nextcloud for a very long time. For me, the Calendar is the killer feature. It Just Works. Everyone in the household has an account

I have been running OwnCloud/Nextcloud for a very long time. For me, the Calendar is the killer feature. It Just Works. Everyone in the household has an account and we share calendars with each other. You can use whatever client you want (Thunderbird, Android, Apple devices) but the web UI is really excellent and easy to use as well. My biggest gripe with Nextcloud is that upgrading between major versions is a pain and they release upgrades often. If my VPS didn't have other duties as well, I would probably switch to a hosted version.