I have a pair of the MBT sneakers that I wear every day all day (yea, I know you're not supposed d to wear the same pair of shoes all the time). I bought them before I had seen any of these commercials for wearing these shoes to get a better butt - the MBTs weren't marketed that way. They were marketed as a way to help people with knee and back problems - other things too probably but all I was testing them for was for relief from a knee problem I was having.
All I can say is I LOVE these shoes. They are the most comfortable shoe I have ever worn, Yea, they aren't pretty, but I don't care, I am all about comfort. They feel like they are propelling me when I walk, it is just lovely to walk in these shoes. I wear a pedometer and get in 10,000 to 15,000+ steps a day in these puppies.
I am a cathlete and as I said didn't purchase them to work on my butt (I agree, nothing works the butt like butts & guts) or my legs. Just wanted my knee to stop clicking and hurting when I took the stairs so I could get back to my beloved Cathe step workouts!
I took them out of the box and wore them all day, never felt sore from them. It never really occurred to me to think that they were giving me a "workout". Now I am a bit embarrassed to wear them though because people ask me if they are the sketchers and I think - NO!, I didn't buy these shoes because I actually think that they will make me have a better butt!