I'm just about to get my first set of MPS4S when I get back to the UK in a few days, after years of driving with MPSS on so that kind of "real user feedback" makes me happier with my choice!
Expect a slightly softer ride but with no real downside to handling, just maybe not feeling as sporty, more grip in dry, lots more grip in the wet.
I've tried to find a new set for the 458, failing miserably as the front size been 235/35/20 seem a really odd size and all Michelin seem to do now is Porsche and Tesla versions, so for now I am just moving my current PS4S to the new wheels as the fronts are perfect anyway. But I might grab a set of new rears as my current rears are around 3mm.