Upsides: They really work. Downsides: Being asked about them at least three times a day from passerby. For colder weather, toe socks are almost required. And they get damp quite easily; that's tolerable when it's warm and you wear the shoe by itself, but in the case of wet & cold weather, damp socks = frozen feet. Despite this I was still wearing them in last week's storm in the Bay Area because, at least at the time, it seemed better to feel cold than to feel clumsy.