While reading your post one thing came to mind (and of course it's an apples to oranges comparison). If you take the cost of a new Z06 and put that money into the Z, you come out ahead in every aspect but one....the warranty. I have no doubt that with the cost of the Z06 you can buy a Z and pay a mechanic to build you a higher performance car....but the warranty makes the big difference.
"The 300ZX Turbo is a dance; it's a song; it's rolling, roaring automotive art. There is no color that doesn't suit it. There is no mood-lifting chemical substance it can't replace." - Automobile Magazine