I have angle of attack in my SS7/rotax 912iS and would not own a plane without it after using AOA. Really increases the safety factor of any approach and is very useful on low speed/short field approachs. I suspect it is part of the answer to the FAA's loss of control issue. A good demonstration is to overshoot the turn to final and increase the bank to compensate. The AOA might read 3 degrees with a normal turn and jump up to 8 or 9 with the
rapid turn to correct the overshoot. On my system calibration, 15 degrees is
stall. Best glide and best angle of climb are also indicated.