No stereotype, or generalization goes for everyone. It is why I don't make my point out to say "all" of them. It is very much a case by case situation. I have met some good looking sweeties too, but the majority of good looking clients I have seen had poor personalities. Not all of course, thankfully. And I can attest to someone with a poor personality does not get better service, in fact they get reduced service and I avoid rewarding bad behavior.
But my good looking sweeties get the same treatment that my non-traditionally attractive sweeties get. It is who they are, and how they treat me that will dictate how well a visit goes. Not how good they look. I have my man, I'm not looking to fill that void, and have lived long enough, and been threw enough crap in my life as an SP, and a civi woman, to tell you never judge a book by it's cover.
My master will let me call him sexy, because he is to me. But if I try to tell him he is handsome, he is to me, but he knows he isn't traditionally handsome, so will stop me and deny the compliment. (LoL, and yet I get in trouble when he tells me I am beautiful and I sneer at the compliment, but I digress.) And he gets better, and more of me than any client ever will, reguardless of looks.