Late to this thread, but in case anyone reading this does a Steam review, ...
IMHO one of the most important elements of AH (and its defunct predecessors like Air Warrior) is the view system, especially the legacy numeric keyboard view system. This type of view system allows instant glances in ANY prototypical direction (not just those in the plane of the wings and straight up), with your brain knowing where each direction is relative to the orientation of the aircraft. This is because each such direction corresponds to a unique hand position on the numeric keypad, thus giving you muscle feedback on that direction, as a real pilot obtains from their neck muscles. So, with practice, your brain knows for example that a particular patch of sky is "up and to the right-rear" relative to the orientation of the aircraft. So although Aces High supports special viewing hardware such as TrackIR, you don't need it to be competitive.
This type of real-time situational awareness yields a big increase in game play value. Because an experienced player has instantaneous, position-contextual information on his target(s) at all times, the player can utilize the full spectrum of real-world air combat maneuvers, as described in such books as Shaw's "Fighter Combat". Contrast this with the pitiful viewing system of such games as the in-development space sim "Star Citizen".