AoA Utility
As I have posted a couple of times before, AoA is highly useful at approach speeds (and in a stall situation) but not for maintaining a desired flight condition while in cruise. When encountering an Unreliable Airspeed condition, flying a specified AoA would not be very effective in cruise. At approach speeds, AoA varies relatively large amounts for relatively small changes in airspeed. At cruise speeds, the variation of AoA is relatively small for relatively large airspeed changes.
The U.S. Navy uses AoA for landing on aircraft carriers because it provides a precision reference for executing a precise approach. AoA indicators have not typically been used in transport category aircraft because that degree of precision is not required, but flying AoA does allow the pilot to fly the correct approach airspeed, regardless of weight and without reference to tables. The P-3, as initially introduced into the fleet, was equipped with AoA indicators but they were routinely ignored because "AoA is for jets". I don't know if those AoA indicators are ever used today.
IMHO, AoA is the single most useful instrument you can have to prevent a stall.