I read Form's explanation again and he said out to 5-600 yards. My brain is starting to get it now and I can see how it would be quick in a limited # of shot circumstances when you aren't aiming at small targets.
My initial thought was well 300 yards and 700 yards are a lot different, how does one pick a bracket.. But if a guy just figured it was set at lets say 500 yards you could have set brackets for certain speeds and just cheat a little if its a little longer or shorter. Most of us shouldn't be extending past that on game anyway. Hopefully a quick and dirty way to land within a couple tenths?
Not sure I'd use it that way but it's starting to click at least.