You on about how much material you get? as in some companys supply their pads with 6mm of pad and others with 8mm? I don't know the reasoning, but some people can't run 8mm or pad because of clearance etc so maybe companys see it from that point of view, and a grind wears pads out fast so the 8mm might be to make the pads last longer If your on about shorter/longer length ways, short pads are bitier, whereas longer pads offer more hold