The Pirelli PZero Rosso’s that came on my S5 have definitely seen their last summer. I was happy with them performance wise and they were nice and quiet on the highway.
Leaning toward the Michelin Pilot Sport 4S despite some serious sticker shock (255/35ZR19 aren’t cheap no matter what) . Don’t need ultra max performance (not autocrossing or tracking the car) but I enjoy the spirited drive and the extra grip/control of a good summer tire. Also not willing to sacrifice ride quality or noise for a little extra performance. I ran Hankook V12 Evo’s on the GTO and was happy with them, but in terms of ride quality and quietness the GTO and S5 are in completely different leagues. I’m afraid the V12 Evo 2 is going to come across a lot harsher on the S5 compared to the GTO where the muscle car background was loud enough to hide a harsh tire. Any other suggestions?