Seriously, the smell. I knew what I was getting into since I had purchased another pair of pretend-leather-plastic shoes from Zappos about a year ago (though they were sold as being actual leather). But, wow. The smell is really intense. I am wearing them every weekday, but store them outside so as to air them out. At this rate though, it will likely take at least 3 months before my socks and whole work space stop smelling like a tire factory. So, the shoes are comfortable, fit as advertised, and are made out of plastic just like the product description states. But, be prepared for a couple months of irritated eyes and wondering whether you're causing irreparable cell damage from the off-gassing.