From what I've noticed, it's definately the quality of the RP that matters more than the description.

The description, as said several times before by several people in several places (do I get a bonus for using the word several that many times?), is only a first impression. However, in text based envirorments, it can't be absolute as their are many people drawing different pictures of what the character looks like in their mind.

Anyway, I think this is why the actual RP has more weight than description in the attractiveness. The picture painted through RP says more about the author's intent than the description does. - Especially how it's discouraged to suggest attractiveness or whatever.

On another note, I don't think it's wrong to make characters that are attractive or whatnot, but I'll admit if I see an overly attractive character who I've never RPed with before, I'll be slightly suspicious. Especially having seen people (that were largely male, in my experience) that must mention their female character's breasts every other pose... but I have seen people whose description suggested attractiveness and been incredibly good. It's just like any other group, you have the good and the bad, I think there is an unwritten set of rules that require 'higher standards' for those who wish to play overly attractive characters though.