[georgyo]

Unstable in NixOS is nothing like the horrors that wait in Fedora Rawhide and Debian Sid.

NixOS benefits from the fact that it has unit tests and that all packages are built in a consistent way across all packages.

Archlinux is a bit more stable then NixOS unstable, but not significantly so. But more importantly if you do somehow manage to update to a broken build, it's take less than a second to roll back to exactly where you were before hand.