Rating: 4 / 5
I do not think superfeet are supposed to prevent blisters, unless because they help correct the fit, they, by chance, correct an area that might otherwise chaffe your skin. Also, cut off about 1/8 inch back from the toe, and taper the cut in the toe area. Insoles help to level your foot. This can be especially critical for skiers who control speed and turning by the edges of the ski. It is impoortant to have your skis flat when standing still, especially if your foot has a natural roll toward the outside. Insoles are a bit like the emperor's new clothes. Unless you can feel or tell a difference right away, it is hard to judge the effectiveness.
It is important to fit these to your foot size, not your shoe size. For example, my foot measures just over 9 standing on a foot ruler, yet I wear a 10.5, sometimes an 11 shoe depending on the model. So, if you wear an 11 shoe, do not necesarily use a size 11 footbed.
Eventually I got blisters just behind my toes. The footbed was too big. This happened after many miles. You could see where the foot bed had worn, by noting a discoloring in the plastic. Bend the plastic and it whitens. The plastic must have been riding back and forth into my toes along the bottom of my feet at the first toe joint. When I replaced the foot bed with a smaller size, it worked in the same shoe as the other that had blistered both feet in the same area.