The courses are all very, very good and all quite different, which is amazing considering how close they all are to each other.
I think Sand Hillis is best right now, but once the Doak at Dismal grows in, who knows. But, more importantly, who cares? Each is a course you'd never get tired of playing.
To give a my word association for each:
Sand Hills - sublime world-class greatness. By far, one of the best I've ever played.
Dismal Nicklaus - a roller-coaster of fun
Dismal Doak - possibly perfect routing that provides everything one could want in a golf course