Exit row seats on at least some A319s/A320s also have the tray in the armrest, which means the arm rest does not raise. This is good if the plane is packed and the middle seat is occupied so the person next to you can't spill into your seat, but I don't like that when there's a good chance of not having anyone in the middle seat. Other airlines somehow manage to have trays in the seat back, even in exit rows, so I'm not sure what's up with America West.