We have a border collie/rough collie mix and he is a great dog, easily trainable and focused on making sure no unwanted four legged guests invade his space. We had a purebred border collie previously who, having come from a working lineage, was almost neurotically enslaved to his herding instinct. If you don't have sheep or anything else that needs herding and are considering a border collie, I would recommend that you get one that comes from pet stock.