Daily use for several years. Nix the package manager has been the bigger impact for me as I use multiple systems, and they’re not all running NixOS, but my nix configs work across them all. As for NixOS, I would not necessarily recommend it for a non-programmer, but if you’ve ever found yourself thinking about how operating systems are assembled from parts, then NixOS could be a very good fit for you.

Mixed. Many folks use home-manager to configure their user environment with nix, and you can specify config files there. However, escape hatches to use regular files not managed by nix exist to make config tweaking faster. You can specify your config file contents in nix, which works well for server deployments, but for desktop use it usually ends up being a mix of seldom-changed config going in the nix definitions, and other things that, say, revolve around GUI tools for config tweaking (eg KDE apps) continuing to do their own thing.

Wow, terrific! Love the tap to collapse, swipe to upvote, etc. Main thing in terms of common reading interactions that I’m missing from Apollo is a swipe action to collapse a thread back to its root. The app is already quite nice to use, though, thank you for sharing!