I the configuration.nix of NixOS is a nice, small way to get your dev machines configured and installed with the stuff you like. Just copy it on your new machine and off you go :)
I don't know if I would ever use Nix instead of the more language specific packet managers.
Nix derivation and nix store managed artifacts is a superior model to many language specific package managers (though the learning curve is non-trivial), we use it with Haskell extensively, for instance.
I can't wait for someone to write a great book on Nix. I was so lost in it. I had it running on my home server, and needing to compile my own things because of what Nixpkgs lacked was a constant struggle.
It was a very frustrating experience. A frustration which was led by the fact that i could tell how powerful Nixos was - if only i could grok it.
Yeah a book on nixos would be valuable I think. Understanding nixos really comes down to reading all the docs then trying to accomplish what you need to do, learning by doing and reading source code.
I love nix, my biggest gripe would be that the Nix language is dynamically typed...
No. They do not. Docker wants to manage containers but nix wants them in the store. I went so far as writing a derivation and tool for pulling a container into the nix store without docker so it could be docker loaded.
At the very least Nix would make your Docker builds more reliable. Granted, you could then start making arguments for "why use Docker at all", but i can't answer that.
I the configuration.nix of NixOS is a nice, small way to get your dev machines configured and installed with the stuff you like. Just copy it on your new machine and off you go :)
I don't know if I would ever use Nix instead of the more language specific packet managers.