Carbon stems for vanity?

For the most part it looks like fancy carbon stems are just for vanity.  Or maybe they are a little stiffer than the aluminum ones but they seem a little heavier on average and I'm guessing that most of the time cyclists just want one that matches their handlebars and/or seat post.  Maybe I'm wrong but I think I'm guessing the "look" has more to do with it that the carbon fiber wrapping that might increase stiffness but double the price.

FSA OS99 CSI