As far as I was aware AMDGPU is used by default on most if not all distros so I still think its a bit confusing to decide which to use for your needs at first unless you check the video I linked. I noticed a performance increase after forcing RADV on NixOS so not really sure.
Sidenote why cant AMDGPU and RADV combine their efforts to simplify and rename AMDGPU-PRO to AMDGPU-unfree because that itself is confusing since most people will be drawn to use the PRO version without realising the worse performance.
I really love NixOS and use it on all my devices. Its not as difficult as people say and it really makes the linux experience a piece of cake once you get it down.
The single config file to control almost everything is just what I was looking for in linux and the fact that it solved any kind of dependency hell I have experienced in the past is huge. If I had to list a top 3 it would be NixOS, Fedora, and Arch.