My Brooks Ghost model shoes often separate in the area between the sole and the upper mesh. This separation begins to occur after the 300-500 miles that I run/train with them, and is limited to the area of the outside "ball" of my foot. However, I'd like to continue to wear them as "walk around" shoes if they haven't separated like this. I've had 5 editions of the Ghost 10, 11, and 12, with three of these five pairs breaking down. I may be ordering the Ghost 13 soon. Anyone else have this issue of separation.