Potenza 950 ???

Just bought 4 new tires (Bridgestone Potenza 950's) for my new Z. I am just wondering what people who have them think of them. Specifically how much tread life should I expect? Has anyone actually made it to 40k, which is how long the warranty lasts. It's bone stock (for now), I won't take it to the track, and although I do drive rather aggressivley I will only burn the tires a few times a year ( at least thats the plan!).

Thanks:D