Re zero retention. Before I bought mine I messaged with our resident rifle-tosser who indicated these are fairly reliable in his experience. Ive only had mine for about a year and a half, but I did fly to wyoming with it—I actually watched a baggage handler through the plane window THROW my rifle case onto the conveyor at least 5-6 feet, plus whatever other bumps and vibrations it gets between northern vermont/chicago/denver/casper. Zero was exactly where it had been, didnt even adjust it a tenth. I also fell hunting here at home later that fall, following a track in new snow here at home. I was on a pretty steep slope and my feet just went out from under me in the snow when I stepped on a dead branch, and I landed full body weight on top of the scope/rifle. Knocked the wind out of me. Checked zero the next day, it was still dead-nuts on zero. It also has none of the small error several of my other scopes have had where I chase zero around a few tenths at a time while zeroing—if your group is .3 mils from center, 3 clicks gets you exactly where it needs to be and it stays there. I cant claim to be the most abusive guy out there and its still only a year of use, but so far so good, its been a very low-drama scope.