I'm not sure about the rears, I did read that it was the same (carriers and discs to change) but I would imagine the change in this 'upgrade' being minimal.
Rather than waste money doing the rears I would put it towards something like an R32 set for the fronts, massive difference that way as the front does most of the braking.
Yes there is a little bit difference you notice on the fronts, in that there is extra pinch.