I've gone full NixOS on my laptop and my gaming/homeserver desktop. I love it (even if there are parts I hate) and will never move to anything "less declarative". 100% no regrets.

However, I only recommend it with the caveat that the practical benefits are not worth the time invested and it's only worth it as a fun hobby. I think an immutable desktop like Silverblue/Bazzite is really the sweet spot.

Nix (non-OS) as a way to define dev environments though? Incredible, would recommend it in a heartbeat. Opening a project and knowing you are going to have the exact versions of all dependencies you need is so refreshing, or seeing that a public git repo has a `flake.nix` and being able to `nix run <url>` and download/build the project in one command is truly magic.

Gonna sound like a lunatic, but I have used AI agents to set up flake.nix for the following things:

- My basic nix-darwin and home-manager setup for my laptop

- Declarative tooling install for my clone of an open source Rust project

- LaTeX setup for my notes for a book club, including creating a nix package inside the flake to install the version of Garamond I wanted. Traditionally, installing LaTeX and non-free-fonts involves running a bunch of commands as root and praying. This is way better.

It took a lot of prodding and telling it things like "you'll know you did it right when `make all` works", but they all ended up working exactly how I wanted them to.