Great at putting logos on your feet
This product excels at putting large Castelli logos on your feet, and little more. It's not really apparent what these actually do as far as function goes. They certainly do not add any warmth to your feet or even do that great a job of keeping your shoes clean. To get them over your shoes, the fabric is stretched so thin that there's no way they are providing any real amount of insulation or even good shoe protection. If the fabric looks thick in the picture, that is only because the bootie appears to be worn over a foot versus a shoe.
They are starting to develop several holes already, and not just where toe/heel touch the ground. The Castelli logo appears to be a weaker stitch as there are starting to be several holes there as well as a small (but growing hole) where the bootie covers the buckle closure thingy.