The addition of the ProLock to the Kinvara has me looking for an older version. The ProLock plastic band that comes up around the arch of your foot puts an incredible amount of pressure on the outside of the foot. I still feel soreness 12 hrs after my run, along the side of my foot, from this plastic band. It is an unfortunate addition to a shoe I have loved since the original version. Unless you have narrow feet, I would take caution about buying the Kinvara 5.