Which ssh-based duplicity back-end should I choose?

Question

I am looking at using duplicity for doing file backups over ssh to a remote machine. I see that duplicity supports multiple back-ends that work over ssh, such as ssh://, scp://, and rsync://.

Is there a reason to prefer one of these back-ends over another?

Answer 1

rsync:// should be able to resume transfer in the middle of the file, so if you are backing up large files over semi-reliable network, I would prefer that.