In my opinion it's best to use the EABCO peep rib due to the fact that it positions your rear sight several inches further back from the front sight. The factory rear sight is really close to the front sight. The longer distance between front and rear sights is going to be more accurate especially on longer shots. The ability to easily mount a scope is also a nice bonus, but not the main reason I like my EABCO peep rib sight on my Optima.