Bibliophile home decor

Apartment Therapy has done a post on vertically stacked bookcases, featuring five types ranging in price from $110 to $298.

I don't know: they might look cool, but I'm just not sold on these as a practical book storage solution. They look so... tippy. What happens if your books aren't centered properly? Does it bend paperbacks in the middle? Crack spines before their time? If anybody owns one, shoot me an e-mail and let me know.