I have owned a 2006 Carrera S with P Zero Rossos and 2006 Carrera 4S with Michelin PS2s. Although I have historically preferred Michelin tires tp Pirellis, I have to put the Pirellis on top. More grip, better communication and improved ride quality at the expense of quicker tire wear and a greater tendency to flat spot when stored for more than a few weeks. I would rank Bridgestone a distant third and would avoid mounting Contis on a Porsche when performance and handling are of greater importance than cost and durability.