This is my second pair o these shoes, and like the first pair I owned, the cracked across the vamp after wearing for more than a year.  The material, though initially flexible, became brittle and eventually cracked all the way across the top.  After making the investment twice, I will not purchase these again, considering the price and perceived durability of the shoes.  My traditional Birkenstock sandals lasted 20+ years, so it is obvious that it is the material that is faulty.  I also tried to follow these up with Crocs which are a horrible substitute.  The search continues...I'm going to try the Stico clogs next!