I perused the Rustic website and they have a direct comparison of Restic here: https://rustic.cli.rs/docs/comparison-restic.htm. At face value I thought it was just, "because it's Rust," but it does appear to have a few additional features.
Rustic was started by a former restic contributor. My impression at the time was that he was frustrated with poor collaboration from restic maintainers (slow/no response to his PRs). So it's a bit more than just "rewrite-it-in-rust".
Many of his rejected/ignored restic PRs ended up being features in rustic: cold storage support, config file support, resumable operations, webdav server, etc.
I switched to rustic a couple of months ago due to it being able to filter based on .gitignore files. Have done a few test restores and everything has worked well so far
A killer feature rustic has over restic is built-in support for .gitignore files. So all your dependencies and build output is automatically ignored in your backups.
Nice. Using `.gitignore` would simplify my Restic, Borg/Borgmatic, and Rsync-based backup scripts/configs. (Right now, I end up duplicating the same information in a few places, not very well.)
At first I thought that sounded great, but then I realized that that would exclude files that I want to be backed up, like `dir-locals-2.el`, which should be excluded from git, but should also be backed up. There doesn't seem to be a great solution to that in general.
Wouldn’t you back up your git repos by pushing them somewhere? Even if that somewhere is a different directory on the same drive. Backing up your local working copy sounds a bit odd.
I haven't used either, though.