Fitzy in PA is worried about his EoTechs. There really isn’t anything to be worried about unless he finds himself in extremely cold weather. The zero shift that is the subject of the military’s concern only happens in extremely cold environments. It has recently come to light that Trijicon’s MRO also suffers from Thermal drift. Since Thermal drift is across almost all optics, anything you put on your rifle has the potential to have the same problem as the EoTech. My EoTechs have served me well in any weather I have had them in in SW PA. Keep your EoTechs and as with any optic, re-zero if you change climates significantly. As JWR stated, L3 isn’t going out of business over this. That they offered a refund to anyone who no longer had confidence in their product is outstanding customer service in my opinion. I’m hoping to take advantage of well below cost used EoTechs as they come up for sale by those who panic over the viability of their safe queen’s optic. I’ll keep mine and buy more. – Rick in PA.