I'm a fan of the Aimpoint PRO/CompM3 series.
The carbine I have set up for my wife (11.5" BCM) has an Aimpoint Pro. That said, my current HD carbine (16" BCM) does not have an optic on it. My HD carbine sacrificed it's Aimpoint to go on the 11.5" BCM, and it's more important for my wife to have it than me. I don't notice a major difference in speed or accuracy between an Aimpont and Irons when I am practicing < 10 yards. Beyond 15 yards is a very different story.