Well even though the Z06 is definitely built more like a track car which you said you won't do, the difference is definitely noticeable in everyday driving. The base C6 is certainly quick but the Z06 is much quicker and handles better as well, it is the lightest corvette available (150 lbs lighter than a regular C6 due to the aluminum frame), the newer Z06 also has much better brakes that are shared with the ZR1. In essence, the C6 was definitely a quick car when I drove it but the Z06 was unlike anything I have ever driven before and I've been in some pretty quick cars. It depends on your definition of speed, drive both back to back and you will see it too.
2jZ + RB26 + 4G63 + LS9 + N54 =