the differences are in the material type, material cut, material bonding to plate, and plate spec. take a look at all the major types available, and compare them side by side, they are all slightly different. The actual differences arent night and day to the daily driver, but the daily driver doesnt exist. everyone drives completely different. you can throw on $150 superpads and rotors and give them to a guy who will chew through them faster then someone else will with the exact same car driving the exact same route...whos more then happy with $20 economy pads. brake fade, dust, heat transfer, surface area, cut angles, "dust" factor, warpage/expansion tollerance, there are tons of factors that in many different sitations will make a good deal difference. the majority of brake complaints come from abuse, poor driving skills/practices, sticky calipers, and #1, inproper or lazy installation and bedding.