Someone correct me if I'm wrong, but the way I understood it, the Viper race cars have them to help cool the driver as the cabin gets quite hot (I do not believe the race cars have air cond). Many on the street want that RACE CAR look, hence the demand for the scoop styling. For some owners, having something on their car that is fake is totally unacceptable, so the option is to make it function.
That being said, The functional scoop does virtually nothing. At 80mph with the scoop open, you cannot feel air come into the cabin unless you crack the window to release cabin pressure. For $395, it is not an option I would spend my $$ on. It is kind of cool having it work, but it does add potential leak problems.
Jeff