Alanjp's 'new' caliper is clearly 'stepped'.
CHECK em out guys as here's a BIG difference.
I'll bet Brembo have changed the pistons from 4-equal daimeter to 2-large and 2-small - as this will push the leading edge of the pad on to the brake disc first (just as you would on old-style bicycle rim brakes to stop brake squeal). Maybe I'm wrong, but so long as it works, then who cares? Go Audi/Brembo, eventually!