i get quite a lot more distance out of my front tires than the rears, and i've heard of a couple people who run softer, grippier fronts than rears (i.e. Power Pilot front / Pilot Road rear; Diablo Rosso front / Diablo Strada rear; etc).
the advantage purportedly is to get better front grip while balancing rear wear.
any comments? (front grip certainly seems more of a limiting factor than rear...)