Pros: Very sturdy; compostable!
These bags are so great. I was worried that they'd be not too sturdy. But they're fantastic. They hold their contents well, and they actually feel fantastic to the touch -- not as "rough" as traditional plastic bags (try one -- you'll see what I mean). Moreover, it frees you from the guilt of using traditional plastic when you're taking out the garbage. Highly recommended.
Also, just found out: Residents of San Francisco (city and county) can purchase BioBags at any Albertson’s, Cala/Bell’s, Cole Hardware, Rainbow Market, Real Foods, Whole Foods, or Walgreen’s Drug stores. Otherwise, can get them online!