I happen to have a Vital Bow Gear Camelback Pendulum and like it a lot. I keep it locked down and sighted at 20 yards most of the time. But when I was trying out the pendulum mode, it allowed me to be dead on accurate from 5 yards on out to maybe 25-30. The only thing a pendulum has a problem with is a downslope an upslope because it can't compensate for the terrain. If you have flat land, then a pendulum can be a useful sight.

Lefthanded Reflex Highlander / Lefty NAP Quiktune 1000 / Lefty VBG Camelback Pendulum