Can This Insulated Pillow Sack Really Replace a Slow Cooker?

Second only to the microwave as the appliance lazy chefs rely on most, the slow cooker is the easiest way to prepare a meal when you really don't want to pay attention to the process. But the Wonderbag promises to further improve the joy of slow cooking by not requiring a power source to finish off a meal. What sorcery is this? More