Love to see more adoption of Nix and NixOS.
I started my Nix journey a little over a year ago, and I regret not having switched sooner. A package-manager that also ships an operating system that can be customized from the bootloader up, using a purely functional programming language is the perfect configuration management tool!
It does have some rough edges, and I did lose some hair figuring things out early on, but it has been getting better with each passing day. Pretty much the entirety of my setup at home is now built by Nix and runs NixOS, including my Macbook Air (runs NixOS on ZFS), and two Mac-Minis that PXE-boot a custom NixOS served by a Raspberry Pi 4 running a custom NixOS configuration that also acts as a firewall connecting wirlessly to my ISP's router. The Mac-Minis also double as build machines which makes for a pretty smooth experience when I'm building anything on my work laptop (a 2020 Macbook Pro running Big Sur) that I dock with my CinemaDisplay, which is wired thru an unmanaged switch to the rest.
So far I haven't missed any packages that I could not find in nixpkgs, or customize just the way I wanted to. The community is pretty responsive and quick to merge any pull requests for fixes/upgrades. I would whole-heartedly recommend switching to Nix/NixOS/Nixpkgs.
There are few bad sides to NixOS though.
The community consists mostly of programmers, which means I am missing some creative tools (mockups, mindmaps, ..). In the future I will be able to provide/build them myself, but it is not a smooth transition from my previous arch setup.
Also the whole documentation sucks: There are three (!) official manuals + the home-manager manual + Nix pills + YT + random blogs where I have to piece everything together.
Still I find NixOS superior to every other OS (windows, linux) I have tried so far. I just feel free and am not afraid to fuck up anything [2], as I can just go to a previous generation when it doesn't boot.
Lastly, I can save my whole config in git and am free to try new tools -- If I don't like them, I just remove their line in my config. No more chasing after random install folders! (Except in home..)
[1]: https://github.com/driusan/lmt [2]: All the "hacker" stuff: kernel modules, network hardening, ...