I think what they mean is it's fully set up, so that if you've never used Emacs and you start using it, you won't encounter the situation where something stinks and your friend who's an experienced Emacs user says "oh, you need to customize such and such." So, "awesome by default" rather than "awesome after many hours of learning about and applying configuration changes." (I have no idea whether what they've done would meet that criterion for a large number of potential users.)