They are beyond fantastic optics, as above, glass is very clear and bright, built like a tank...in fact the owners manual says you have to tap three times on the turret after making an adjustment or it wont move!!! They hold zero like nothing else made................
But there is a problem. Ever notice when you see the Marines on the news doing a "sweep and clear" in Iraq that they have the rifle sideways and have the buttstock of their M4's sitting on top of their shoulder??? No, they are not gangsta...it's because the ACOG has about 1/4" of eye relief. You have to sit the stock on top of your shoulder so you can get close enough to the eyepiece to see a full field of view!!! That kills it, sorry...wish I had better to say about these scopes. I cant even believe the military bought them. For the money, which is not a little bit, one would think they could have designed in a usable amount of eye relief!!!!