He said the 100 calipers were larger than the 80 calipers. Replacing old worn parts with new parts, properly bled, was night and day difference for him. How much is due to 100 calipers vs maintenance for is up for debate.
He said that the pads overhung the rotor slightly, like 1/8th inch. Now that I think about, if 80 calipers place 100 pads completely over rotor while 100 series calipers allow a slight overhang, that would REDUCE swept area and thus performance.
So 100 series calipers will bolt on front and rear, whether that's a good idea or not is a different question.