They reach full grip at higher slip angles, so the steering doesn't feel quite as responsive. For lack of a better analogy, they made my car feel a bit nose heavy, even though the tires (225/45-18) are only 1 pound heavier than the Bridgestones.
So you lose a bit of that telepathic, instant turn-in response. Not much, but it's there, even though I went with a zero toe front alignment, which is supposed to help turn-on. I don't know what they'd feel like on the stock suspension, because I already added Koni FSD's and a 32mm Tri-Point rear bar, but they seem to understeer a little bit more at low speeds, which is where most of that sensation comes from.
Fortunately, unlike the stock tires, they don't squeal or scrub off speed when they do slip, so at low speeds you can simply drive the understeer, you'll just need a bit more steering input. At higher speeds, that mostly goes away though, and with my setup, the rear end is more involved so the car becomes neutral. But even the rears need a higher slip angle before they really hook up, so it takes some getting used to.
Basically, they have much higher limits than the stocker's do, but it takes a bit more skill to get there, and keep it on line. This improves over time as they wear though, which helps. They're very predictable and easy to drive at high slip angles, and they grip like mad and don't slow the car down when they slide, you just gotta be ready for it.
Especially when new...do NOT rip through the first offramp on the way back from the tire dealer/installer! They need time and heat cycles to develop full grip, and bigger eggs in your basket to get the most out of them. I was pretty annoyed with them for 500 miles, they were sliding all over the place, but I beat on them pretty hard for about 50 miles in the local hills, and they finally started to work. Now, my biggest worry is trying to stay in my seat!
The other issue is choppy roads. Even with my FSD's, which are superb on choppy roads, the Star Specs create a lot more steering kick, which adds to the nose heavy feeling. They're still very driveable and have plenty of grip, but the car will be a little more "skittery" over poorly maintained roads when you're really pushing hard.
The paradox though is that ride comfort over choppy roads is actually better! Can't comment on wet grip yet, but people say they're very good. But the dry grip is phenomenal, you just have to man handle the car a bit more to get it. Like I said the steering doesn't feel quite as precise in daily driving or when you approach the limit, but the other virtues more than make up for it. And they're reasonably priced and look awesome with stock springs. But they demand more of the stock dampers than the OEM tires do, and the stock dampers aren't very good at all. I'd change those before messing with any other aspect of the suspension, including tires.
Anyway, not trying to scare you away from them, just letting you know what my observations and opinions are. I've got 1000 miles on them now and I love them. It just took a while to fall in love with them because they don't work very well when new, and they numb up the steering a little bit. But the nicer ride quality and phenomenal grip are well worth it. You just have to be patient and wait for the grip to come to you. And it really helps to have track experience so you're comfortable with their higher slip angles if you want to drive them quickly on public roads.
