Many smooth collie owners feel their collie has more energy and are more clownish, compared to their rough counterparts.
My smooth tri-color, Cleo, has put on her many antics for our family and makes us all laugh at home. She actually prefers to sleep on the couch when she is expecting puppies. Each dog is different in some way.
Smooth collies have the qualities the traditional rough collie does with a variation. They have a tight, smooth coat instead of the long rough coat. They only shed twice a year, just as a rough collie does. Most short-haired dogs shed year round.
Genetically, they can carry both the smooth and the rough coat gene, producing both coat variations when bred to a rough coat. They are 100% the same breed as a rough collie is. They just have a different coat style.