I thought I'd provide an update to this thread...
My father took his six-speed Cayman S to the track two weeks ago. This was his second track day ever. And just like a 20-something with two days under his belt, he was too hot into every corner on his first session. Once I got him reeled in, he did pretty good. His reflexes are a touch slower than most, but adequate. Most importantly, he had a blast.
...Oh, he's 87 now.
The Cayman performed quite well. It's an easy car to drive, and pretty darn quick. Still, my old 911 has that hard-core feel that can't be replaced. I'm glad I decided against buying a Cayman too.