I've had a few sets of these on Porsches. First on a 981 GT4 and next on my 718 Spyder. To be honest, had I known our they were equipping these on a convertible from the factory, I would have optioned for the no charge downgrade.
I had another GT4 that had a competitor's tire on it. Driven back to back, there were definitely different characteristics. I always described those Cup 2's as 'plinky' as that's the sound they'd make over any bump, even with tire pressures lowered. My wife and I also had similar observations of heavy steering response on the GT4, but I understand the desire for straight line stability in a car that is slated to do 180++ MPH on the track.
There's lots of differences between our previous 981 Spyder and the 718, but my single biggest complaint with the car seems to fall on these tires. The previous generation was equipped with a competing brand's high performance summer tire. Obviously, there was less grip most of the time, but if we got caught in the rain, no big deal. Also, the non-track tires were very predictable making the car a breeze and a pleasure to drive.
I do not track the Spyder... it's a convertible meant for the street in my opinion. Porsche's website has a few warnings added to it now about hydroplaning with the Cup 2's. I haven't had the car in the rain, but if these are similar to the ones I had on my GT4 several years back, they're borderline dangerous in the wet. Also, at lower temperatures (less than 60 F), these are extremely unpredictable. It's hard to criticize a track tire for that, as at the track I would be using tire warmers or at least a few laps before I started to push the car. But, for a street legal car, I can't fathom the purpose of their purpose.
My complaints with the tire fall mostly on how numb the Cup 2's feel with extremely heavy turn in. I feel like there's an extra layer of compound on Michelin tires that make them seem soft and disconnected from the road... almost like your riding on a set of tires on top of a sheet of rubber on top of asphalt. Accompanying this seems to be the heaviest steering I've ever felt in our Porsche's. I noticed the numb feeling with my PS4's as well, but I don't mind it with those considering they are on a daily driven GTI. But for a simple roadster, I prefer to feel the imperfections of the road with nimble steering response.
Unless someone is very competitive in amateur racing, has lots of money to dispose of, or just wants that extra second off of their lap times, I would opt for PS4's or a competitor of the PS4's.
I want to be on the Michelin bandwagon, but I just can't see what all the fuss and cost is about. The street characteristics really are unacceptable even if you're claiming it's meant for the track. I've run slicks at multiple tracks from multiple manufacturers, and have turned near identical lap times between them for given conditions.