Sport Auto recently performed an acceleration test (0-300 kph) involving six cars. Summary of the results. (First figure 0-100, second 0-300)
Koenigsegg CCX: 3.8/21.9
SLR 722 3.8/29.6
Murci LP 640 3.3/31.5
911 GT2 3.7/36.2
Alpina B6 S 4.4/41.5
Z06 4.1/44.6
The CCX is clearly the fastest, and overall the results are in line with the relative power of the car. Nevertheless, that the heavy B6 was faster to 300 than the Z06 can be directly attributed to the top gear characteristics of the Corvette. It may result in low revs, and low mileage, but the flip side is that it will take you some time before you reach top speed. (However under the current traffic situations, even in Germany, the tall top gear might be the more sensible solution...)
Edit: For easy reading press the "quote" button first, then the figures will appear in nice columns.