Ray S

I have had Michelin Pilot Sports, Conti Sport Contacts, and Pirelli P-Zero's on my cars (in addition to Kuhmo and Michelin R-Compounds).

I'd say the following;

Wear - Conti's are the best with Michelin a close second. Pirelli's are lousy
Noise - Conti's and Michelins are the best. Pirelli's are noisy.
Dry Traction - Mich Best, Pirelli Second, Conti third
Wet Traction - Conti and Mich best, Pirelli worst
Street - Mich overall best
Track - Mich overall best (non R compound street tire)

GSIRM3

I have Michelin PS2 on my 997S, but had Continental Conti Sports on my last M3. My first two M3s had Michelin PS1. I did not track the M3s, but for street use, I thought the Conti's were every bit as good as the Michelins. I think many people automatically assume the Conti's are not as good as the Michelins simply because of name recognition. In Europe, many drivers prefer the Contis over the Michelins. There is absolutely nothing wrong with the Contis.