Actually, the research follows that the more attractive you are, the better things are for you...jobs and other things are always more easily within reach. Up to a certain point. People who are considered 'too' good looking also run across something I'd call the intimidation factor. (This according to those studies someone referenced.)
And anyway, I think all of us know things are more complicated than a simple duality. IE, yes it is true that women have an issue with 'the pretty girl' sometimes. And no, she really has no wriggle room to be nasty among those women. If she has a couple flaws, too, perhaps, you can bet those same women are on them like the plague.
Straight men of course think being physically appealing is very important...I've noticed this especially, however, among men who are not considered traditionally attractive themselves. Seems like they also then place the beauty quotient on women. Which is kind of weird...like having an attractive woman is to make up for their lack of attractiveness somehow. Some women (especially the less self-assured ones) fall for it, especially if they value $$ and the man has that. Most women who value their own satisfaction do not got for it.
I've seen situations where overweight and unattractive was the norm, and everything is easier for those people. Game theory (A Beautiful Mind), even proposed that although everybody wants the gorgeous blonde (supposedly), people choose someone they don't think will reject them... And though I don't really necessarily believe that...there are huge and varying factors in preferences of any sort. For instance, intelligence and expression there of--in appearance and demeanor--may be paramount for some. Relatively unattractive and/or overweight people who have style and are neat, clean and competent I think are always judged better than sloppy, stupid and not-so-bright physically attractive people. At least at a certain professional job level.