I have laid out several different shot angles in my CAD software and the only need I can see for the arc is super steep angles. When I laid out a 20 ft stand height and a checked the actual shot angles from that height, at 40 yrds it made less than foot difference than from the base of the tree, 30 yards just under 2 feet diff, 20 yards 1 yard diff, and here is the kicker at 10 yards it made a 6 foot or 2 yard difference. If your stand is at a lower height the difference will decrease, and of course increase if your stand is higher. I used 20 ft as that is the average height of my stands. With the speeds of todays bows, in my opinion the arc technology is a wasted cost. I have shot at 3D tourneys with a buddy that has one and we would often get the same reading because of the rounding of the yards.