[kibwen]

Note that Fedora has an immutable version of the OS that's similar in intent to NixOS. It's called Fedora Silverblue.

[Filligree]

I've tried it. And while I'm not sure why, its updater never worked for me -- hung while downloading, I think, but there was no feedback.

Honestly, I prefer NixOS. It's far more configurable, which is a nice thing to have in an immutable OS.