I have no expierence with Pirelli tires. But I can say, I swear by Bridgestone G3s. I have used several sets on the track and they work for heavy cars like a 5-series. They are actually better the Potenza S03 in the wet. Dry performance is a bit down (slightly). Its the best overall balance for spirited driving, great side-way strength for serious cornering.
I went thru Conti Sports Contact 2 (not bad but expensive!), Yoko AVS Sports (good but easy to wear out, stick on hot days), Dunlop FM901 (pretty bad, hard and noisy, take too long to warm up!) and Yoko ES100 (average tire). The Z-rated G3s are great value. I think its a silica-based compound!.