RE: Pendulum vs One-Pin Adjustable
If you go with a pendulum style sight check out the Predator IV pendulum sight. I've used them for the last 8 years and bought one for my father-in-law and he loves it too. Even at ground levelit works great and you dont have to lock it in like I hear you do with the Keller. As far as noise, the way it pendulums it is very quite.