It's all about the skin, each gleaming, crisp scallop of which bears a slender, super-tender cargo of meat and fat (which shouldn't need the hyped-up hoisin sauce it's often served with).
Nai Mong Hoi Thod (539 Thanon Plaeang Nahm) sells nothing but oyster omelettes, crisp from tapioca flour and long-frying on an ancient, seasoned wok in rendered pork fat.