Although my yorkies have always been under 5#, I also have a 16# smooth coat chihuahua. I get all kinds of comments on him for his size. Mostly, I think they think he is a pom. But they always say 'he's so BIG'! He is still small to me, but I certainly can't carry him around like my yorkies.
I would almost think that there would be more knowledge about yorkies out there. It is, afterall, one of the most owned dogs around. Seems like with so many people either having one or knowing people that do have would know a little more about the breed.