Data wise, it's mostly the same. i use syncthing to a couple different systems, one of which is essentially a storage server. The main difference for me is the app installations. apt install all the apps, then configure each. Kills a whole day for me. I'm sure it can be automated, maybe ansible / salt / . But the way I use it, Nix enforces that I always update my configs in a manner that is easily restorable.
Copy my backed up system into /etc/nixos/
Run nixos-rebuild boot. Reboot.
Setup syncthing. ? Profit