There is a sort of seam, covered with thin rubber, across the top of toe box which does not flex like the rest of the soft, breathable, sock-like material. In my case this seam put slight pressure on my big toe toenail causing discomfort. It seems foolish to have this restriction across the top of a toe box, especially one that is relatively narrow to begin with. I only walked around for a few hours and decided to return these shoes. Yes, otherwise very comfy.