MBT is perhaps at the top of the heap when it comes to rocker bottom wellness shoes. They have found a way to add class and style to this shoe niche. I am very happy with my purchase. I'm an athlete and play lots of basketball. I bought these shoes to strengthen my legs  and improve posture and balance. You however need to be cautious about just how effective this shoe is. The first few weeks these should be worn sparingly. I wore mine every day for a week. I felt my calves getting sore and tight. They were indeed getting a workout as advertised. Problem is I did not recognize how tight these muscles had become and went to play in a league playoff game and had pulled by right calf muscle within five minutes. I managed to finish the game but I knew this injury was related to the shoe. You must respect this shoe. You must gradually use these in increments. They do tax the leg muscles and make them work harder. This is what you want. But it must be done slow and easy. I own 2 Tambeas and two Fanakas and the quality is excellent. Lots of technology in this shoe and the leather is thick and tough. Warning don't do any competitive sports while your breaking these in. Stretch you legs like crazy and do either manual or electrical deep tissue massage on a regular basis. Since I was the BIG athlete I thought I don't have to follow the directions which are clearly written and strongly advise a gradual approach. You live and you learn. Sometimes the price to pay for one's own ignorance is more pain.  Heed my advice and don't make the same idiotic mistake I made. This is serious technology and must be treated as such. Slow and easy is the only way. Buy the way I also like the Ryn shoes which are a bit more stable. MBT makes their shoe more unstable on purpose to force the muscles to do the stabilization. There are Ryn days and MBT days. Either way the gradual approach is mandatory.