Scopes are definitely better for picking out openings to shoot through but irons are not without their merits. I'm partial to aperture rear sights. No need to worry about the rear sight, merely look at the front sight and put it where you want. Your eye naturally centers the front sight in the aperture without conscious effort.
I find that if casually shooting offhand at clay targets at 100 yards, I'll break more with irons than with a scope. My theory on it is you are more relaxed with irons because you don't notice every little movement and try to correct for it like you do with a scope.
