I've got GP4000s.

I just replaced the rear after about 2,300 miles. There was still at least a third of the tread left on it, which I thought was impressive, but it had several deep cuts, and I'd actually got a flat from cr*p that had worked its way into an existing cut. It was my second flat on the tire, and I'd already bought a spare since I wasn't sure how many miles I'd get out of them, so I went ahead put the new one on. I've had one flat on the front, just recently.

I like the feel. They seem to stick reasonably well in the turns, but I don't corner super hard. I rarely brake all that hard either, and don't remember anything particular about these tires under very hard braking. They do have a considerably more "triangular" profile than the Michelin Lithions I'd run in the past (like Dunlop motorcycle tires, if that helps anyone), so they turn in a lot quicker but might feel a little twitchy or take a little getting used to. I've never used them in very wet conditions, so can't speak to that. I admit it, I'm a fair-weather rider.