This is a work in progress and definitely isn't at the point where, for example, a Ubuntu user with little technical background could switch over easily.
As many commenters have pointed out, users will still be questioning which options they should change to accomplish a goal and will need to use a search engine.
To alleviate these problems, our next major step is "Guided Configuration"[0]. This will allow users to select a task (e.g. add a user, add a group, configure your desktop environment, configure sound, configure bluetooth, etc) and be provided a list of options relevant to the task.
Additionally "Recommended Options"[1] will inform users of options relevant to their current configuration which they have yet to define.
There are a few other smaller changes in the works to help with usability, and I'm open to suggestions for how we might continue to improve UX and make configuring NixOS intuitive.
Also, if you've used Nix-Gui, please consider filling out the UX Survey: https://github.com/nix-gui/nix-gui/issues/129
[0] https://github.com/nix-gui/nix-gui/issues/77 [1] https://github.com/nix-gui/nix-gui/issues/21