I’ve used Chronosync to back up two iMacs to a home server for years. (Backblaze backs up the server to its cloud). It can suffer from sluggishness, and indeed it was taking way too long – hours each day for an incremental backup. Then I discovered their ChronoAgent program which massively speeds things up.
I use Chronosync to backup files from my linux server to my mac and then they are slurped up by Backblaze. I own CCC but have never really figured out a way to use it. Whenever I do clean installs, I prefer to just manually reinstall everything.