For those who also belong to OT, there is a thread there about the '05 GTO. I don't feel like copying everything over from there, I don't have time.

http://forums.offtopic.com/showthread.php?t=1164393

Cliffnotes:
with optional sport appearance package

without

The 2005 GTO's advertised acceleration

0 to 60MPH automatic - 4.6 seconds

0 to 60MPH six-speed - 4.8 seconds

1/4 mile - 12.9 seconds

'03 SRT-4 50 trim turbo + support