Gaynor Mindens come in 5 different shank strengths and do not wear down as they are not made of the traditional materials such as fabric and glue but instead of a special kind of plastic. If your feet tend to break down traditional shoes quickly, you would probably do best with the hardest shank strength (green bag). Even Svetlana Zakharova has switched to Gaynors, and with her amazing feet, if she can wear them, anyone with flexible feet can!
One of us wears Grishkos and she loves them! She has very flexible feet and she feels that they last longer than other traditional shoes as they are so incredibly hard.