Yes, Michelin Pilots are THE best tires I've ever had... As for weight, remember the S4 is more of a GT than a dragster/track whore... If your that serious about track times, who's gonna gut the interior, add rollcage, etc... on a brand new S4? Seriously?
There's nothing better than going into boost on the highway when an unsuspecting adversary pulls up on you... Audi's are sleepers. I am always getting from others, what the hell is under the hood!!! And in Avant trim? forget it. The look on people's faces when they're being pulled on by a station wagon, lol, that's the best!!!!