I've worn Gravity Defyers for about a month, most recently for two weeks in Spain, which has lots of cobblestone streets and uneven surfaces. The shoes' heels' contact surface is only 2-7/8" wide whereas the entire heel width is 3-3/4". That inequality makes the shoe laterally unstable, especially on uneven surfaces. I would not buy them again. Other than that major shortcoming, the shoes are comfortable.