[pxc]

I'm too tired and busy atm to really write up a comparison like that atm, but on this

> I have a gut feeling that having reproducible builds/installations gives 90% of the benefits Docker provides.

I'd argue that both tools provide more benefits than Docker, at the cost of the extreme convenience Docker offers in allowing you to use completely arbitrary (even non-reproducible!) steps to produce a container image. If you're already using either tool, you can achieve anything Docker can, including deploying against the Docker runtime. See the docs for the `guix pack` and `nix bundle` commands for info on how either tool can automatically produce OCI images out of arbitrary packages for you.

(To compare the two tools, I recommend just installing both Nix and Guix (via their own usual installers) on some desktop Linux VM and playing with them.)