I've used both Borg and Restic pretty heavily. I settled on Restic because it was much lighter on resources. A few of the servers I manage have small amounts of ram, but large amounts of data. Borg would often get oom-killed, but Restic wouldn't.

Restic also starts uploading changes as soon as it sees them, whereas borg has to scan the entire list of files before it starts uploading changes. Unfortunately for multi-tb datasets with millions of files, borg would take hours just to scan all of the files.

Pruning old archives also worked a lot better in Restic compared to Borg.

If you're happy with Restic, I'd keep sticking with it.

Restic looks pretty interesting, I wasn't aware of it, thank you. I don't know how Restic can achieve its goals, since AFAIK you need a binary running on the server to diff/check data/verify restores/etc without transferring all that over the network.

Borg runs a binary on the server to do this, that's why it can't easily back up to S3 et al.

One big disadvantage of restic at the moment is that it doesn't do compression (https://github.com/restic/restic/issues/21).

I was using restic and switched to borg because of that and could save hundreds of gigabytes.

Restic also works on Windows, whereas Borg doesn't (yet), if that's a consideration.

I've been quite happy with Restic, doing always-incremental encrypted backups to S3.

Borg is also big on deduplication