It is actually slower than Ubuntu which can be see with the recent git update BUT if you know you need this patch or update it enables you to achieve that with

It is actually slower than Ubuntu which can be see with the recent git update BUT if you know you need this patch or update it enables you to achieve that with overlays pretty easy and fast and if you know what you are doing you can reduce the rebuild amounts to near zero. You also need to remember that behind NixOS there is not a big corp like canonical but mostly a community with way to much time. If you ever tried to build an Ubuntu package with a custom patch you will know how painful it is and unmaintainable. Not with nix. Easy maintenance included with automatic, atomic rebuilds and applying the patch to the next software version if the source code didn't change.