My guess the only real difference is underhood temps will equalize quicker when parked. Need to mock up some yarn telltales to see if any air movement is there when moving, and in which direction.
I would assume, any air movement is good air movement, but if there is enough to cause a pressure change under the car, that could be bad (but I doubt it). Does the Base crossfire have that seal? I know the Base has less sound deadening, and maybe that is the primary purpose of it?