[tombrossman]

> Is anyone using such tools as a backup for their NAS (and then using their NAS for time machine?).

Do you mean backup to the NAS or for backing up the NAS itself to a third location?

Either way, there's no need for an either/or approach. Just do both. I've tried multiple backup applications and many support local and remote backup options as standard. I'm using Borg and Back In Time and with Borg it's just a second cronjob with nearly identical scripts for the off-site backup over SSH. With Back In Time I was using the AWS CLI to push the backups to S3, but I found a better deal with cheaper storage. I have about 200GB data in total but want a 1TB archive available online for older backup sets.

Side note - OP's review is helpful but Borg Backup is oddly listed under 'Attic', which it was forked from years ago. Don't bother looking for Attic if you are comparing backup tools available today.