With my federal ss 595's 17/255's only on the rear of the car.
They have suvived a few burnouts,numerous drifting antics,a track day,a skid pan day and regular street driving and still have tread on them.Even if below 40%
I attribute allot of this to having nice even tyre wear from the rear camber kit.
I mean i cant comment from having ever driven a car with good tryes long enough to make an educated guess as to what was the best value tyre for money.But,going from my dads car and his bridgestone potenzas and their wear after only 1 track day with regular street driving,they are holding up quite well.