I used a Keller for about 3-4 season. It was dead on accurate out to about 35-40 yards. I took several deer with it and would still be using it had I not gotten a new Guardian last year. With the speed of todays bows, pendulums are almost obsolete. The only downfall about the Keller sight was that it had a decent bit of vibration when taking the shot. That said... I never had a deer duck or jump my shot because of it.