 It is a lace-free shoe. It weighs less than the latest iPhone does. Designed to be more adaptable, dynamic, and supportive than your average running sneakers. The $330 shoes already have a convincing track record, that is. A Kenyan runner, Helen Obiri, an Olympic silver medalist, and the only woman ever to have won indoor, outdoor, and cross-country world titles, won this year's Boston Marathon wearing them.