I have semi-flat feet and I find that running shoes with arch support give me blisters.  These shoes are comfortable right out of the box and ready to go.  They are light, breathable (so much so that you actually feel the wind through your socks), and cushioned in just the right spots.  The gel must be different on these, because I can literally feel the impact disperse on every step...no more shin splints either.  Looking forward to buying an extra pair because these might be the most comfortable running shoes I've ever had.