I use nix-darwin + home-manager (with a sprinkle of homebrew) as my daily use dotfiles config for home and work, and have for the least year or so. It works great, after some initial growing pains.
There is a trivial fix for spotlight which makes it work correctly. You can view it here: https://github.com/natecox/dotfiles/blob/3c9b493afd893c0ebd0a355b81ad81f99fcfcdf2/modules/home-manager/default.nix#L40