I thought Pirelli had more options in terms of the tire compounds and construction.
Mind you, don't remember where I heard this, so I'll be the first to admit I may well be full of shit
nope, you get a choice of A B or C usually.. about the same amount of choice you get in GP. but the Pirelli's have a must softer carcass. you can push them around and square off corners.
besides, you'll never hear any one in GP complain about the 'stones having enough grip. they reportedly have you-just-can't-believe-it grip. obviously last year they had a lot of getting up to temp problems, but those seem to have gotten better. the 'complaint', if you can call it that, is that you have to literally build the bike around the tire. but building it around a tire that has ungodly grip doesn't seem like much of a punishment.