Terrence asked of AOA systems, so standby for conflicting opinions.
Here's one. From my experience flying F4s (USAF) and several Navy ac (Naval TPS) the only AOA presentation that is visually in concert with contact flying (eg base to final turn) especially in a deceleration pattern: the presentation indicator MUST be in the field of view as the pilot is looking out of the cockpit, past the instrument panel. An indicator on the instrument panel is only more good data like airspeed, but requires refocus, and does not deliver the information where it's needed: in the field of view.
Therefore, the challenge is to get an appropriate indicator mounted above the glare shield and as far forward as possible.
Additionally, the visual must provide intuitive reaction by the pilot and not require interpretation. The Alpha Systems chevron indicator provides this. The donut is "onspeed" and the chevrons suggest to the pilot what to do with the stick. That is why thousands of military fighter pilots in millions of hours of flying, have come to see this presentation as the appropriate standard for instant visual recognition of the AOA right now, when micro seconds count. (However, the Alpha Systems probe is troublesome for a couple of reasons.)
One que the fighters of the 60's did not have, is an aural in the headset that said "Angle, Push, Push," and that too would be an excellent and valued que for quick response by the pilot. Unfortunately the aural que doesn't indicate how much to push forward, and when is it ok to ease back again. Whether that evokes the desired flight response as quick as a visual in the field of view would require testing. In lieu of that, I believe an aural signal with practiced pilot input would be a good contender for use with head-out-of-the-cockpit contact flying, where it's most important.
The May 2012 issue of Aviation Consumer does a good job of describing AOA systems available. It only lacked in not emphasizing enough that an intuitive visual indication IN THE FIELD OF VIEW is the most useful in preventing death and destruction. Think donut and chevrons.
Jack Addison
LNC 2 hi comp, no AOA