I just can’t go back to Debian or Arch after this, I’ve tried.
I have had this feeling for some time as well. NixOS puts you on a power trip -- you can bring up and tear down systems in seconds; you can relentlessly experiment without repercussions; your repositories work reproducibly.
But I also learned that whether using NixOS is productive very much depends on what software ecosystems you are working in. When I was primarily doing Rust for work in Emacs, it worked marvelously.
When I switched to CLion (for various reasons), cracks started to show. CLion does not work well in combination with nix-shell, so when you switch often between projects, you end up with projects that don't build because you are not in the right environment. Currently, I am doing more Python development, and that is an absolute pain with Nix. You end up needing different sets of package versions (which are not packaged in nixpkgs) in different environments. If you need to change multiple packages in tandem, you want mutable state. The best you can do is to make a FHS environment with buildFHSUserEnv, which kind of works, but is not very smooth. At which point you realize that you are basically fighting the system.
Then there are the niches that are not well-covered. Over the past year or so, I have had to do GPU profiling more recently. Last time I tried, the usual NVIDIA tools (e.g. Nsight Systems) worked very badly on NixOS. Of course, it's a big proprietary blob with all kinds of FHS assumptions, but you need to get work done.
These are not all failings of Nix or NixOS, it is more that there are a lot of software ecosystems out there that are not really prepared (yet) for an non-FHS, immutable world.
but I’ll be damned if it’s not a preview of the future
I think for most Linux users, Fedora Silverblue is probably more of a preview of the future. It doesn't have all the features that NixOS provides, but it does have many that matter (immutable base system, atomic upgrades/rollbacks), while going further than NixOS in other departments (verified boot, SELinux, git-like store of blobs). It sticks to FHS, so a lot of existing software continues to work.
Edit: this comment is about NixOS on the desktop. I think the server is a completely different story.
Another approach is to use a main stream distribution in combination with the nix package manager. You can then always fall back to the distributions native packages.
I have had this feeling for some time as well. NixOS puts you on a power trip -- you can bring up and tear down systems in seconds; you can relentlessly experiment without repercussions; your repositories work reproducibly.
But I also learned that whether using NixOS is productive very much depends on what software ecosystems you are working in. When I was primarily doing Rust for work in Emacs, it worked marvelously.
When I switched to CLion (for various reasons), cracks started to show. CLion does not work well in combination with nix-shell, so when you switch often between projects, you end up with projects that don't build because you are not in the right environment. Currently, I am doing more Python development, and that is an absolute pain with Nix. You end up needing different sets of package versions (which are not packaged in nixpkgs) in different environments. If you need to change multiple packages in tandem, you want mutable state. The best you can do is to make a FHS environment with buildFHSUserEnv, which kind of works, but is not very smooth. At which point you realize that you are basically fighting the system.
Then there are the niches that are not well-covered. Over the past year or so, I have had to do GPU profiling more recently. Last time I tried, the usual NVIDIA tools (e.g. Nsight Systems) worked very badly on NixOS. Of course, it's a big proprietary blob with all kinds of FHS assumptions, but you need to get work done.
These are not all failings of Nix or NixOS, it is more that there are a lot of software ecosystems out there that are not really prepared (yet) for an non-FHS, immutable world.
but I’ll be damned if it’s not a preview of the future
I think for most Linux users, Fedora Silverblue is probably more of a preview of the future. It doesn't have all the features that NixOS provides, but it does have many that matter (immutable base system, atomic upgrades/rollbacks), while going further than NixOS in other departments (verified boot, SELinux, git-like store of blobs). It sticks to FHS, so a lot of existing software continues to work.
Edit: this comment is about NixOS on the desktop. I think the server is a completely different story.