I have both and I love both. But the C6Z performs like a supercar right off the showroom floor. If you're just talking about all around performance, the cost difference between the two cars is justified and dead on. It's more than just the extreme acceleration you get with the C6Z. A Camaro can be modded fairly easy (<$10K) to run with a stock C6Z at the dragstrip. However, it's the combination of braking, cornering, and acceleration of the C6Z that has it outrunning Ferrari F430's and Porsche GT3's around race tracks. People say it all the time, but there is so much truth to the statement "it's a street legal race car". The only way to truly appreciate what that car can do is to drive one on a roadcourse or hitch a ride with an instructor driving one on a roadcourse. You'll then understand why it was the GM Halo car before "Big Daddy" got here (ZR1).
On the other hand, the Camaro is a beautiful American Muscle Car that can be made to be as fast as you want in a straight line and just having some fun on the street. Most people I come across seem to prefer the looks of the Camaro over the Vette. I've made some appearance mods to my 5th gen that really makes it look mean. I definitely get more attention in that car than my C6Z. My SS "looks" faster than my Z

. I've had it almost two months and on two separate occasions, I've found people taking pictures of it. That has never happened in the Vette.
Both cars make a lot of sense and save a ton of dollars given their performance levels and looks. They are GM home runs.