The first 3 points are pretty much covered by nixos too. 1. It's source compilation based, but you download the cached result if it exists. 2. Unfree option has

The first 3 points are pretty much covered by nixos too. 1. It's source compilation based, but you download the cached result if it exists. 2. Unfree option has to be explicitly set if you want that for specific packages. 3. Depends on the tastes, but it's pretty easy.