FWIW - I have tire insurance on my 911S, and will be getting it on my 08 M3. Porsche (as well as some tire companies here in town) all said repairing a puncture on performance tires was a bad idea. Either way, due to nails, a nasty pothole and more nails - I got my money's worth x10 out of the insurance. My Porsche had tires replaced under insurance at least 3-4 times including one wheel fix after nasty pothole incident.
Performance tires are too expensive and too vulnerable, so I will always get the insurance.