primarily cost versus wear. I just got my Conti DWS's on this weekend. hellacious rain this morning, heavy water, and NO hydroplaning, great stick to the road. Much lower roadnoise than the Conti OEM's and total intalled price was 950. They also are one of the few UHP tires that have a 50K warranty, and the dealer said Conti is good about the prorated wear. Apparently they understand that if you have the UHP's you've got a car that you'll use that feature from "time to time". The Hankooks though for summer are also a very good tire. I just needed more of an all season for my weather conditions.