This is an excellent article. That said, holy shit those are going to be <i>loud</i>. The Wing drone hovers at 24 feet while it lowers its payload? The others descend entirely to the ground? They're typically going to hover just a few hundred feet above the ground? If these are roughly as loud as the quietest DJI drones (and I suspect they will be louder as they are heavier and have larger payloads), they are going to be incessantly annoying.