I have nix on a VM where I am tuning a config. It seems like a total pain in the ass to have to get everything set up using their scripting language. Things you just take for granted with a normal distro now require you to know the arcane language of Nix to get running.
I can absolutely see the advantage of it though. I would love nothing more than to take my current popOS install, settings, configs, etc and be able to port that literally anywhere.