i just picked up a impact cosmic w/ a large aperture, taking off my hha optimizer lite - which is a great sight. not enough usage out of the cosmic yet to give you a definate, but i lost a shot last year right before pitch black - i could see the deer until i drew the bow. i got a no peep, and finally got it just right, to get rid of the loss of visuals caused by a peep in low light, and went to the lg aperture cosmic for this reason also. also i have a blue l.e.d. light rigged to barely illuminate the sight and no peep, because any sight light i have seen actually provides too much illumination and creates a light halo that is difficult to see through in low light. the cosmic was too easy to install and sight in. it is a single pin and the movement of the slide isn't as 'clean' as the hha and requires the loosening of 2 thumbscrews instead of the 1 required by the hha. the variability of distance you can shoot from is increased with the cosmic system though, which i like. the pin is easily as naturally bright as the hha as far as i can tell. i am big into single pin sights, its just less confusing to me.