Has that been your experience?
With Ubuntu, Debian, and even Arch, it's pretty much install and go.
Also, it requires significant disk space, which I usually don't have on my laptops.
I'm also waiting for the parts of my new desktop to come in and I'm excited that all it takes is cloning my config repo and applying to get to exactly the same setup. With Arch I would have reinstalled to clear the cruft that has accumulated, however with NixOS I can just audit my configs to see an entire list of cruft and easily undo it by removing lines.
One of my hobbies is recycling older machines. I've installed NixOS on Chromebooks with 16GB internal drives. It's possible if you remember to garbage collect after each successful upgrade (and stick to 64-bit machines).
I tend to treat my laptops as disposable and keep my important data on a file server so I don't rely on local disk space.
I do the same, except I use an extensive dotfiles, config, and bootstrap script repo[0].
So I like the idea of Nix for that reason. It's going to be hard to let go of Debian/Ubuntu, but I'd really like to have a perfectly reproducible environment like Nix.
Thanks for your reply.
0. however, I also unfortunately have to use Windows sometimes,so I dual boot, and that takes up significant room on my smallish laptop drive
If you just want the ability to install arbitrary versions of packages along side each other/have painless roll backs/bake config files into your install you can do that there.
Once you get comfy with nix on top of another distro then think about whether you want that approach with the entire stack.