I have 4 rifles with large aperture peep sights, they work better than open iron sights for a couple of reasons - when in a hurry, you don't tend to shoot high like you do with irons, and they allow older guys like me to shoot more accurately because you don't have to focus on the rear sight at all, just look through. I find my rifles with a low power scope (1.5-2.5X) just as quick, they have all the advantages but they aren't as nice to carry one-handed.