well if all tires are the same for DD, why are you looking at summer performance tires? There is defnitely a DD difference between an RE92 and say an RT615. The biggest difference you will see in DD driving is resposiveness and that is typically from the sidewall stiffness. The sticky rubber will wear fast, and will tend to cup as well.
I am not saying that there is no difference between something like the Azenis or Star Specs and the Generals. My current summer tires are Falken ZE-512's (summer performace) and they suck for a lot of reasons. Having run both them and a set of Azenis in AX, I felt a mayor difference. But on the
street I could
not feel one bit of difference. When I changed my springs and swaybars there was a big difference in cornering feel on the street but we aren't talking about suspension.
I agree, what we are talking about is basicaly sidewall stiffness. Summer performance tires (any one, take your pick) are going to have a stiffer sidewall than an all-season. Yes, the top dollar ones are going to be stiffer but my point is that, on the street, the difference that you feel (because cornering forces, ect are not even close to motorsports realm) is so small that it just does not justify the price.
And yes, the top dollar ones have a more sticky compound, thereby increasing grip, cornering speed, ect. But once again you aren't going to be feeling the difference enough to justify the added cost plus the decreased life.
I DD highway 50+ mi each way, I like a responsive tire if I take a back road, but I want something with 50k+ miles before replacement.
We are on the same page there. All seasons aren't going to be stiff enough (good enough performance) but I still want a long lasting tire and I don't want to spend an arm and a leg. Hence, the Generals. And of course, they are going to last a hell of a lot longer than my Azenis (with street only use, let alone AX) and the ZE-512's cause they wear like crap.
Hell, I don't even feel a signifigant difference between my 16" winter tires and the summers. It is there, it's just small. And it doesn't bother me one bit in my daily driving.
To sum up my thoughs:
If you want performace, buy summer performance tires. But there is no reason to buy top of the line. Buy the cheapest one that has the expected tread life you want. If its for motorsports, but the most expensive one you can afford.
If you don't care about performance then the longest lasting all-season that you can afford will work just fine. Except in one of the seasons, winter.