I don't see Dimitrenko giving either Klitschko that much trouble, he seems athletic enough, quick hands and feet for a big guy, but he doesn't have a good jab, he doesn't get a ton of leverage on his shots, I think either brother is too technically sound and physically gifted for Dimitrenko to beat. Wlad and Vitali aren't the fastest heavyweights ever (even thought their speed, especially Wladimir's, are/is tremendously underrated), but they possess such good body coordination for big guys and they know how to not get hit.