I've been curious about NixOS for quite some time. Reading about it I couldn't see how the config sharing capabilities, setup, or rollabck would be better than Arch and sharing the list of installed packages, using downgrade or chroot.
So I decided to run NixOS in a VM and I'm still confused. An advantage I can see for NixOS is its better use of cores and parallel processing for packages install.
It's clear that I'm missing something so please help me understand what it is.
Edit: Thank you to everyone in this great community! It's always so nice to have a constructive and sane discussion.
After reading so many comments, they all confirm what I've read before and I may realize that my real problem is already having a stable system and no need for the great NixOS options that are very neat but would not benefit my specific and simplistic needs.
That being said I can't refrain myself from being curious and will continue testing NixOS.
The need for only 2 config files is the top of the iceberg but hiding more complex configuration to rely on. Not that I really have too much spare time but I do enjoy learning and tweaking NixOS. With its current development state, things are changing a lot so it can keep me busy for months. That's probably what I was mostly looking for: another toy to play with.
Along my journey I will learn a lot about NixOS and may find a feature that will motivate my switch to it. Thanks again for all your precious feedback!
I'll also take this opportunity to share the best help I've found so far to start with NixOS: https://github.com/MatthiasBenaets/nixos-config And his 3 hours (!) video: https://m.youtube.com/watch?v=AGVXJ-TIv3Y
I'm currently working on rebuilding a Debian web server that's been around for 10 years and accrued configuration over that time in NixOS. It's nice to have one single easy to understand file that fully defines the server and can be used to rebuild it if needed.
I can see that from a server maintenance point of view. After having read so many great things about NixOS, I may have exaggerated my expectation and I may be the problem for being a user with too limited needs to get the full benefits of NixOS.
For me this single config file doesn't save that much additional files and most of them would be files you configure only once during installation. Nonetheless I can see how "easier" it would be to save one file instead of 3 to reproduce your system and I can only imagine how much better it is from a server point of view.
You might be selling it a bit short. I am not a Nix user, but like you I've played around in a vm. The value proposition I see for "normal" users is when you end up tuning and configuring your system just the way you want it (everyone knows what I'm talking about--it happens over months or even years). In nix, you have to do those changes in the config so you can literally take that one file, plop it somewhere else and it's your computer.
Likewise, I've been on this install of Pop for years and for several upgrade cycles. The amount of cruft; things I've installed and don't use, config changes I made while following a tutorial then forgot about, manual tweaks for things that have been officially patched, etc. it would all be in a nix config for me to just... remove.
So I see that as the benefits of it.
That said, it definitely gives me vim vibes. Where the learning curve is pretty steep but once you master it, it's close to tech Nirvana. Again, since I don't use it I can't say that for sure. Maybe one day I'll have enough time to devote to it to really dive in. Right now, it's frustrating to use because everything is harder and there aren't many guides on how to do basic things like get dash-to-dock plugin working on popshell. Or even install and configure neovim. Ain't nobody got time for that right now.
Great feedback, thanks! I've appreciated being able to replicate my system in NixOS within only few hours. I found NixOS actually pretty easy to take a grasp on, though I still didn't look at flakes in detail. You spot on the reason why I'm using Arch and a bunch of applications you can tweak to perfectly meet your own specific needs (neovim, neomutt, bspwm, rofi...).
I love spending time to config them and to learn new things. This is basically why I'm interested in NixOS as well. Being entirely satisfied with Arch and not being a distro hopper, the fact that I installed NixOS means a lot to me but now I need tangible reasons to fully move to it. Maybe time will help me in my decision.
All the great feedback in response to this post so far confirm how great NixOS is and I had no doubt about that. I may realize what it can bring me after some weeks of serious use. Thanks again for the time spent to write your feedback, very much appreciated