They are both almost the same in performance but not by much. Current Z06 0-60 3.9seconds 1/4mile 11.9seconds Topspeed 180mph(est) Price 50,000 C6 0-60 4.3seconds 1/4mile 12.6seconds Topspeed 186mph Price 44,000
Overall, I'd rather have the C6 at this point. Looks tighter, is finished better inside, and I generally prefer the liftback body. Stock vs stock, the Z06 should still probably lap faster (although much of that probably comes down to the tires). Top speed on the Z06 is actually closer to 174.
The Z06 is really slower than the C5 which has a topspeed of around 176mph? WTF????! i think i will take a C6.
I think it comes down to gearing, and the fact that the regular coupe version of the C5 is more aerodynamic than the hardtop Z06.