I have Dominators. Our LBS owner said that the only real difference between the Genius and the Dominator is tread. Otherwise the uppers and soles are the same. My hubby has Genius(es? heh.) and I have Dominators. They seem to be equally stiff. You could always get the Dominators with carbon soles if you really wanted stiff, though I am quite happy with my plastic-soled Dominators. They are nice for walking a small bit into convenience stores or across grass and such.