My Audi RS4 was fitted with Pirelli P Zeros from new. The handling wasn't great and reversing off my drive, the front wheels used to 'chatter' on full lock.
I changed them when they were half worn for a set of Michelin PS2's, which were quite an improvement. However the Michelins began to crack on the shoulders, and I was never quite as enthusiastic about them as the Michelins on my Omegas.
Last year, I decided to change them again - wanting an RO1 tyre, the choice was limited, but I ended up going for Pirelli P Zeros again, after reading many favourable reviews.
I am very impressed with the new Pirellis - a lot more than the Michelins. It seems that although they have retained the name, the tyre itself has been improved with different compounds. Reversing off my drive is greatly improved too with no 'chatter' on full lock.
In short, I'm very happy with the new Pirelli P Zeros

I have also driven a good number of nearly new Porsche's with them fitted and the handing and driving characteristics have been excellent in my opinion.