I used to wear "Birks". The only thing is...they wear down (the cork on the souls) and my feet just go back to hurting.

With the "Z's", once the spring heal wears out (they say you'll KNOW by your gait), you just purchase replacement coils..about 40 bucks a pair....much cheaper than the original shoes. And, they say, the shoes really don't wear out! I definitely can see that. They are wonderful!!
_________________________
Southwest Body Gear here ~ NEWLY updated website with many new products!