I have a Papillion and my Yorkie. They're about the same size. Baron is 7 pounds @ 1 year. Sammy is 15 pounds @ 7 years. Baron has alot of energy and Sammy is a slug. I've seen other Papillions that are not over-weight that act very much like my Yorkie. Sammy and Baron are both really laid back and not barkers. I think the 2 breeds are similar in behavior.
Hope this helps...