My short experience (two weeks) with the ATN reflex sight is a mixed blessing, at best. It is bulky, sits up high on the pistol and adds weight. I would prefer a smaller, lighter, less obtrusive sight that doesn't change the overall look of the MKIII. The reflex sight is less bulky than the standard red dot sights, but...still bulky. Main advantage over the standard red dot is the field of view is practically unlimited. In my opinion it is just OK; a sight step up over the factory sights....and if your old eyes are as bad as mine are, you need some help like this.
One distinct disadvantage of this particular sight is the location of the standard 3 volt lithium battery...you have to remove the sight to change batteries. You have to get used to aquiring the hologram reticle as well...when you first turn the sight on, you think it isn't working until you move the pistol slightly down to pick up the floating reticle...it isn't like looking down the mechanical sights...mine was shooting pretty low when I first started adjusting the elevation screw. Sighting in was easy, though and only took a few shots to zero. Really bright sun is a problem and you have to turn up the intensity to the max, but the reticle is visible in bright sun, unlike some reviews I read that said it wasn't. The more I shoot it, the better I like it (within the objections I listed above)...I read a review of the Burris Fast Fire and it was similiar to my experiences with this sight only my sight is a lot easier to adjust and zero than the Fast Fire. The fast Fire is a whole lot smaller and less obtrusive than the ATN, so....that might be a better choice, although everyone says the Doctor reflex sights are tops...they are also pretty pricey. For less than $90.00, the ATN Ultra Sight seeems a fair value.
