I've found that letting air out of tires often does not make them ride softer. The reason is that tires with stiff sidewalls, like the summer tires on our Caymans. If you let air out, the tires ride more on the sidewalls...and they're not soft!I run 30 front and 28 rear only because the city streets in my town suck big time and I want the tires softer. I've got just a little under 20k on the original 18s and they are starting to skip when I pull out of a tight parking space and they are getting noisy so I plan on going to GY Eagle Sport All Season and will go with the oem specs for tire pressure. I don't track the car so......
My tires skip when I turn hard. Have from the day I bought my CGTS new. The reason is limited slip on the rear doesn't want the car to turn...in extreme turn angles, it pushes the car straight. There's also some geometry going on with the front wheels. They camber more as you turn. At extreme angles, the tire is not flat on the ground.
If your tires are noisy and hard riding, go ahead and get new ones, but even new tires will "skip" at full steering lock on a Cayman, especially one with limited slip diff.