I've been wearing nothing but MBT's since I first tried them. I had surgery on my knee a few years ago and find that most regular shoes result in my slamming my heel down first when I walk, making the knee progressively more tender. With the MBT's this isn't possible. i don't think it's doing anything for the shape of my legs, as advertised, but it sure is a relief on the knees! The only reason I don't give it 5 stars is that the soles wear awy fairly rapidly compared to other shoes. The first time I encountered this phenomenon I figured it was because I was wearing the same shoe, day in and day out. Then I bought another pair and alternated. The new pair wore down fairly quickly. So this time I bought 3 pairs at once.  These sandals I bought for the summer and indoors during winter.  I've never been a sandals guy, but I like these.