For a long time, I was a huge rsnapshot fan. It never did me wrong. I switched to borgbackup about a year ago. It is great. I love that it compresses, dedupes, and detects bitrot. After today I think it is even better.
The total size of the backup is about 7 TB. I re-organized more than 4tb worth of files. I ran my standard backup to the same repo as usual. The total filesystem used only grew about 20 GB which was the size of the movies I have added since the last backup. If I would've used rsnapshot as in the past, my 8 TB drive would've filled long before the backup finished. Borg was able to dedupe the files regardless of their location.
To make it more interesting, I am backing up from an amd64 machine to an arm64 machine (nanopim4). I needed a file I deleted a few months ago. I listed the archives in the repo, mounted the archive I wanted, and copied the file to the location I needed.