"Meanwhile, I'm thinking of sudden stops and crash safety. How is a lightweight structure designed to hold passengers aloft—sometimes not even sitting forward—going to handle an emergency landing that gets a little too rough? I can't help thinking that the problem that they're really addressing is http://www.newyorker.com/business/currency/airlines-want-you-to-suffer ."

"Yeah, it might be interesting to see the chi-squares on some of those.Ultimately, though, the balance of the die is at least as important as any more cosmetic design choices to the target market. I would expect those selling them to take great care balancing the design.The other factor is that said target market can be stridently vocal, even shrill, and its membership talks to one another. If a flawed design rolls out (so to speak), I would expect the designer to get called out on it tout suite."