Gents, I think the amazing thing is the perspective of time. It has only been about 10 years that Sand Hills GC has been up and running. Yet, it is legendary. In part, that is because of unique and adventuresome place where a journey of discovery and wonder at the unique land environment is involved to even get there. It is sort of a golfer's "City Slickers" concept where you drive through long rolling treeless and sand dune horizons of cattle country, that get your juices flowing before you even get to the golf course.
Wild Horse is still in the populated I-80 corridor. Thus, you don't get the wonderous journey effect to pump your adreneline.
Now, with Prairie Club in Valentine about to take shape, and BallyNeal opening soon, there are going to be more destinations of similar experiential effect. As Adam has said, and from the little I've seen in mid construction, BallyNeal has the design bones to go with the "getting there" experience.
Once these sand hills, prairie dunes courses have been around about 10 years, as Sand Hills GC has, I predict that "Sand Hills golf" will be a general term, not a specific one identifying just Mullen. Folks will barely care which of these courses they get invited to play. It will just be a magical regional destination where glorious golf will be available in multiple locations and "sand hills" will mean a unique golf experience, not a specific course.