If you make the switch you won't be able to tell people you use Arch, so keep that in mind.

• NixOS has been around almost as long as Arch (20 vs 21 years)
• you can install the Nix package manager on other distros as an intermediate step to start to give you the feel of things – ie. use Arch to manage your system packages and use Nix to manage your user & GUI packages
• the Nix repository has more packages and more up-to-date packages than AUR
• two recent videos making the rounds on NixOS
  • NIX OS: the BEST package manager on the MOST SOLID Linux distribution – The Linux Experiment
  • NixOS is Mindblowing – Chris Titus Tech

I've also been distro-hopping, but settled on NixOS. I find it very clean, you know exactly where your (system-level) configuration files are (...and could even manage user-level config files using home-manager). There is a stable branch, which is, well, stable. And even if it wasn't, you can rollback the system at any point, which is trivial (just select a different generation during boot).

One of the biggest advantages for me is universal reproducible working environments. Using Nix+direnv, I can lock all tools (make, gcc, JupyterLab, Python, Julia) that I'm using in a project to specific versions (and upgrade/rollback). I can install programs/libraries in a nix shell and they will be removed on the next garbage collection. Upgrades are extremely safe: I once had a problem with RAM that corrupted a lot of my files during an upgrade. Nix can detect and repair this.

Downside is that Nix doesn't follow FHS, so some programs need a little help, for example by Nix' steam-run.

NixOS is as mature as arch, I'd say, but because of its nature it has issues here and there, but rarely so.

That said, the learning curve for nix/nixos is very very very steep, so good luck learning. It took me a while for me to use it nicely, and even then, I'm nothing more than a beginner. Even so, I'm quite comfortable and pretty much can't use any other linux distro.

I switched to Nixos after reading a lot about it and eventually switched back to arch because I didn't like how hacky everything felt. On the surface it seems really clean because of the central configuration file and the reproducible nature of the whole thing, but in the rare case something doesn't go as planned, it's hard to know how to do anything about it. Basically everything that would have been a configuration issue for you to fix, is now a bug. Also, I found no easy way to install software that isn't in nixpkgs (which is rare, but happens).

I would recommend you give it a shot. Nix is not conventional and you will find that the ways you’re used to doing things are arch are done differently on NixOS. It’s not a matter of maturity. It’s a matter of use case. I use it on two systems, but not my main one because there are some things that I don’t want to deal with that NixOS imposes. I encourage you to give it a try and see what you like about it.

I haven't used NixOS but it does sound interesting. From what I gather all you need is your configuration.nix file to rebuild the entire system the same as it was before. I think for sure the biggest thing I would miss is the AUR.

I've been distro-hopping for quite a while. I've settled on Arch for the long haul.

I just made a post about my musing on NixOS so maybe read that? (here) Basically after the main learning curve it's pretty easy to use.

I'm getting the hang of their package manager as well, so if need be I can make my own (Like I would for Arch. The AUR scares me from a security standpoint).

My main advice is to not go against the curve. If the manual says that NixOS does it that way, do it that way, because going against the grain is like going through a cheese grater in this OS.

Unlike Arch where you can do things as you want, in Nix you do things using Nix. You can almost always accomplish what you want, but it's gotta be done the NixOS way. This is actually a benefit rather than a problem once you get used to it, because it starts becoming second nature, and it is extremely powerful.

there is nothing to miss. Watch this : https://www.youtube.com/watch?v=AGVXJ-TIv3Y

You can install Nix on arch to try it out without changing your OS.

I've never been able to daily drive Nix, or for that matter stand using it in a VM. I've always hated every aspect about it. I currently use Arch, but for stability reasons am switching back to (probably, might end up going for something debian based) Fedora on my desktop.