This overlay feature sounds attractive. It bothers me that there is no easy traceability or undoability when I perform random system-level Ubuntu configuration file edits to make things work on my system. Maybe I'm doing it wrong. Sure I could do the professional sysadmin thing and keep a log book of every configuration change, or maybe switch to NixOS and script all my configuration changes, but something with lower effort would be welcome. Ideally you want the equivalent of "git commit -m<explanation>", "git diff" and "git log" for every change you make to system configuration.

CachyOS and openSUSE have you covered with btrfs and snapper pre-configured to take snapshots before/after doing potentially damaging things (and, of course, you can make them manually, whenever the thought occurs to you that you're entering the "danger zone"). You can boot into a snapshot directly from the boatloader, then rollback if you need to.

Immutable distros just one-up that by trying to steer the system in a direction where it can work with a readonly rootfs in normal operation, and nudging you to take a snapshot before/after taking the rootfs from readonly to read-write. (openSUSE has you covered there as well, if that's your thing; it's called MicroOS).

Both of those distros use KDE by default, so the value-add of KDE having its own distribution is basically so they can have a "reference implementation" that will always have all the latest and greatest that KDE has to offer, and showcase to the rest of the Linux world, how they envision the integration should be done.

If I were to set up a library computer or a computer for my aging parents, I would choose openSUSE Leap Micro with KDE, as that would put the emphasis on stability instead.

> Ideally you want the equivalent of "git commit -m<explanation>", "git diff" and "git log" for every change you make to system configuration.

If you already commit all your changes, anyway, what keeps you from using Nix and running one more command (`nixos-rebuild switch`)?

I keep my /etc under Git. When the system does changes automatically (via an update or whatever), I make a Git commit with a special distinct message, and so I can easily filter out all my own changes.

Etckeeper does that for changes to /etc https://wiki.archlinux.org/title/Etckeeper

> something with lower effort would be welcome

This is a major reason I ended up with https://getaurora.dev. I layer a few things, but it comes with bells and whistles (like NVIDIA drivers, if you need that).

I can't see myself going back to a "normal" distro. I don't want to spend time cosplaying a sysadmin, I have things to do on my computer.