here is a link to the tirerack comparison.. yes the pss rated higher, as did all others. but its not a vast difference.. they are all very close... and as stated the pzero is a aged tire the have been making it for a while.. as for the others are all new.. pirelli will make them better very soon... but not for anything.. a tire as old of a construction as it is, the performance that it give it hung right on top with them all...
from that i chart i dont see a vast difference.. i see a small difference that the average drive would not be able to tell the difference.. besides the tread wear i will be the first to admit pirelli wears fast..
Tire Test Results : Clash of the Titans: Testing Two New Max Performance Summer Heavy Hitters