Not size, but tread design and road holding.
For years, I've had Dunlop GT Qualifiers under my car. I've read several reviews of them, and nobody appears to like them very much, but I've always gotten good results from them. Unfortunately, for me at least, GT Qualifiers have been discontinued.
I've had two sets of Goodyears (one was Eagle GTs, can't recall the others) and they didn't perform nearly as well; the compound seemed too stiff, and the tires lost traction without much warning. I've also had Goodriches, which seemed to hold the road well, but wore much more quickly than the Dunlops, and didn't have nearly as good a feel. On various cars I've had Yokohamas, Bridgestones yadda, yadda, yadda.
So, since my fronts are shot, I'm looking for recommendations for replacements.
Two obvious things. First, none of this is scientific. I didn't put the car on a skidpad and measure what it was doing. Rather, this is just my "seat of the pants" reaction. If you have scientific evidence to offer me that's great, but your seat of the pants results are just as appreciated. Second, there are radically different designs available within any given brand. If you want to give me tread designs that have worked for you, that's appreciated as well.