Jon C - Washington I have owned two of the 512s with excellent experiences with both. First off, Eotechs glass and durability is excellent and the donut of death reticle is a standout and is my favorite up close reticle. A great combo with a 512 or any Eotech is a magnifier as the good glass and crisp reticle with a 1moa center dot makes taking longer shots a breeze. One model I tested was made in 2011 and the other a 2017, they had a few external differences but were otherwise identical in quality and function. Both held up well on all of my guns including short barreled .308 AR-10s. They hold zero very well and have held up very well to drops and submersions in mud and water. Some of the downsides are the obvious size and weight (11oz) versus other smaller cheaper red dots that also have 20-50 times the battery life. The Eotechs 1000 hours is pretty low but it isn't designed in the same way or for the same purpose as those other red dots and utilizes very common AA batteries. These are meant to be tough and reliable in more "professional" environments. For being quite tanky optics with great glass they are still high value as well compared to Aimpoints that can cost twice as much.