I have to disagree with that 100% The only thing that may be a upgrade over a C5Z would be the interior which is hardly anything to brag about because they both suck ass. Im not a creature of comfort so I didn't purchase the car with the hopes of getting high grade Italian leather, nav, blah blah blah because Corvettes are notorious for crap interior up until recently with the C7. The C5Z is the better of the 2 cars when it comes to performance.
C5Z has better power to weight, Better suspension, More aggressive gearing in the trans, Stronger diff, Lighter, Consistently faster in the corners and around the track. "Not to mention if you compare the top 10 fastest list between the C5Z and C6's The Slowest C5Z on that list is still faster then the fastest on the C6's". All around it has a more raw performance feel that even a C6Z cant compare to, which is what the car was designed to have. Don't get me wrong, I like the C6 a lot. But when it boils down to it the base C6 is a everyday driver vette for a older man. The C5Z is for a performance enthusiast right out the box. Now the C6 is hands down better then a C5 coupe all day. No contest to that. But when it comes to the Z06 they are 2 totally different cars with different intentions. Even the Z51 still doesn't outperform it in the corners. These are know facts.
And like I said, Nothing against the C6 but my money is with the C5Z when it boils down to the 2. Your entitled to your opinion obviously, That is just mine and im not alone nor are you. Its everyone's preference.