I would disagree as well- on the new market this is the case but in the used market it flips as the enthusiasts grab up the used performance cars...
Look at the difference in prices between A4 and M6 used f-bodies, 6 spd vettes versus autos, hell even 5spd mustangs versus slush boxes and nissan 240 sx's.
Autos are faster 7/8 times out of 10 at the dragstrip due to driver error with manual cars and difficulty to launch.
I predict my dad's 08 vette A6 will own me at the strip and my car makes more power and is lighter...