I had big problems with OwnCloud. Specifically it ate files at work, but did so in such an insidious manner (slowly, over time, with no indication that anything

I had big problems with OwnCloud. Specifically it ate files at work, but did so in such an insidious manner (slowly, over time, with no indication that anything was wrong) that I don't trust it to this day. I haven't checked lately, but the issue was acknowledged by OwnCloud devs, with the workaround being to "use a secondary sync application" (no kidding). These days I use Seafile, and I can also say that your suggestion of Syncthing is a good one. I have used and enjoy both Syncthing and Seafile. Just a word of advice: Don't trust Seafile to encrypt your data. Use Veracrypt (or equivalent) in place of the built-in "encryption" offered by Seafile.