I use owncloud cause of the additional features it gives, multiple user, shareable links, android photo upload, RSS reader, collaborative documents. I don't run the apache+sqlite plugin freenas offers, but instead run it from source. owncloud isn't a backup, I use offsite zfs replication for that.
if you just want simple syncing to your computer syncthing/btsync are more geared towards this. this+snapshots could be considered a backup.