The original reason we tested back in the alpha\beta was Hitech had chosen 85 as the default FOV when you first installed the game. Players like ourselves would not be the norm, while first timers would probably use a mouse. So the slight down angle was to allow those first timers with a mouse and 85 FOV to see the default instruments needed for flying. I will venture 100% of veteran AH players hit the HOME key and then F10. Now that the default FOV has been changed to 90, and you can drag a HUD display under the gunsight, I'm not even sure that light down angle matters and it may even contribute to turning off potential new customers trying to see out of their cockpits.
I wonder if for some new customers setting the default back and setting the default for the speed and direction HUD just under the gunsight will be more attractive and familiar.