I wasn't knocking your procedure for backup, but I am familiar with the advice stating not to consider owncloud a backup utility. I do not use Owncloud for backup, but I am sorta interested in looking at a way to do it.
I currently have a 3TB seagate goflex home NAS that I use for backups of PCs and my Owncloud server data/config/DB.
What I am interested in is backing up files on my laptop remotely to NAS which has SFTP capabilty, however the security protocol?? is out of date and newer SFTP protocol are not compatible with it. I have mapped the NAS as a network location on the server so that is a workaround if I wanted to go that route. At this point I am just rambling on, however I could just SSH, or SFTP to server and copy to network share I guess. I have looked at "Easeus ToDo backup free" at one point but I believe it is/was limited on storage locations.