I've read that PBS requires fast (NVME-fast) storage and a decent CPU to handle incremental backups efficiently. What speeds do you get when restoring backups?

Using BTRFS.

Just reading of the logs:

- Backup duration: 3.21GiB in 36s

- Restoring a Snapshot: feels like <<1 minute

HDDs work fine for me with PBS, and I get regular 120mb/s HDD speeds when restoring backups. Honestly how often do you restore backups anyways?

Well you should do that frequently, at least to make sure you have restorable ones.