I normally wear size 9 1/2 and usually have no problems.  This pair was so tight my toes almost touched the front interior of the shoe.  There is some additional material on the inside sole which is why it didn't fit.  I read reviews on this shoe and there were others that had the same problem.  Replacement shoe was much better.  The upgrade to size 10 solved the fit problem.  There is a buildup of material in the sole and tongue of the shoe requiring one upgrade in fit.