No matter how much I tried, I always had crappy experience using OwnCloud (-> very slow to recognize new files and sync them across other computers). I tried it maybe 4-5 times in total, last time just couple of weeks ago.
Does it work fast for you? Do you use desktop client or primarily web GUI?
I tried it too, but ended up replacing it with something else. It was slow as a pig, was unable to handle datasync with failures and timeouts on any reasonable amount of files (a 2000 file user) and constantly made my CPU fan hit max.
My server was a Core i7 with 12GBs of RAM, SSD backing and a more or less dedicated NAS. I tried with both SQLite and MySQL backing. MySQL was better, but still unacceptable. If that's not enough to run it for a single user, I can't imagine what it's like trying to deploy it for a full family, even less an organization.
I love the idea behind owncloud, and I admit touting it myself in my own "honeymoon phase", but in hindsight I have no problem admitting that the execution is just too poor.
Same experience. I tried it on DO droplets (1, 2, 4 and then 16GB of RAM to see if I'm nuts), computer I'm working on (16GB RAM) and from a RPi (that was for fun though). Every single time it was painfully slow.
It took it about 1h to sync a folder with about 100 files, under 30MB total across 4 computers. Not to mention that minor modifications appeared only after 15 minutes (small text files).
BTSync worked great, but I wouldn't trust it with something sensitive.
Long story short, I went from an "all cloud" (Google + Dropbox) setup to a "all mine, no NSA" setup. Now I've decided that counter zealotry doesn't have that much for it, and I'll try to balance privacy with best of breed services, without trying to end up with all my eggs in one basket. Not doing that ensures I keep interop and portability in mind.
My end-result is calendar via Google (only solution I can get collaboration and invites working properly), files via Dropbox, mail with Fastmail (much better than Gmail) and contacts via Baikal on my own hosted server.
Fastmail is adding support for calendering and contacts via CalDAV and CardDAV, but I've yet to fully investigate that.
It's a moving target for me, but currently it's been stable for a few months, and I'm mostly happy.
Yeah, it was completely unusable for me (a few months ago). It ran a separate process for each file upload, taking a few seconds minimum and completely serial. I estimated something like a month and a half to do the initial sync of 100GB, with a mix of large and small files.
Does it work fast for you? Do you use desktop client or primarily web GUI?