i sight in on 10-20-30-40. probably could use the 20 for anything under 20 but i like the added security of the adjustment. i used to use a 3 pin sight(20-30-40) when i started bowhunting and it sucked trying to see the deer around the multiple pins. 1 pin is the way to go.
i sight in with the pin dead on my intended point of impact, anything else is just more complications added to the mix at the critical time of the shot at the deer. wasn't sure if i wanted to trust a pendulum sight so i use the HHA adjustable and love it.