I think there is a lot of overthinking going on in this thread. A larger rotor and more clamping force with everything else being the same and adequate, will result in shorter stopping distances. I upgraded the 2 piston calipers and tiny rotors on my 02 trans am to the 4 piston brembos off the base c7 and the stopping ability, distance and repeatability improved substantially. A properly functioning, properly bled system will function fine with the increased piston surface area but most people won't take care of their brake system and then complain about spongy brake pedal feel.