Pretty much what the last couple guys said. They are cheap, so they aren't exactly built to make any kind of difference. They are mostly sold just to make a car look cool. I would know, I have a cheap ebay set in my car. They will flex under the pressure of me pushing down on them hard, so what would make me think they could handle the amount of pressure a car would put on them and still function the way they are supposed to be used? Basically you're paying $50 for shiny metal that adds some character to your car. Honestly, there's nothing wrong in that, but some people like to give other people a hard time about it.
Like anyone will ever tell you, it's your car, do what makes you happy.