I am a very strong proponent of Aimpoint sights. You really cannot go wrong choosing any of the Aimpoint models. When I was with my hometown police department, I was the only officer on the force with an Aimpoint, I carried an ML2 (purchased 2003). This Aimpoint was with me when I was on the Firearms Unit and testing for SWAT. There was a lot of discussion about the Eotechs on the department in 2004 and 2005. The department decided on the Eotechs for issue optics and I just could not understand this. Every time I had to do an entry, there was always one guy with an Eotech, who had a dead battery. The guys on the team where changing batteries monthly or every several weeks. I never had an issue with my ML2, it just kept going strong year after year.
I am still running my original Aimpoint ML2 on my personal home defense Colt LE6920. In fact, I am on the original battery from 2003. The only thing I worry about is possible corrosion, as the battery has been in it for almost ten (10) years now. I have simply kept it in the ML2 and on the rifle this long, to see when it will finally die.
Now you may be thinking, It has never been left on and has not been through any hard use. I will tell you that it was in a rifle mount on patrol, in a Crown Vic, for almost four (4) years. I used it as my primary Instructor Rifle Optic and Patrol Rifle Optic, on several Colt rifles, LE6933, RO933, LE6921 and an LE6920 for several years. The optic has seen more rounds on rifles than I even know. It has been though countless training classes, entry schools and instructor schools. When it was on duty, the ML2 was on for an average of ten (10) hours a day four (4) days a week.
For the past six (6) years the ML2 has been my home defense optic, on a Colt LE6920. I do not keep it on all the time but it does get used a lot. Mostly during range time now and Loose Rounds articles. It is still going strong and I’m sure the battery will die soon. I tried to do a rough calculation of how many hours it has been on. The only hard number I could go off, was the roughly ten (10) hour duty times. I estimated about 8060 hours. I know it has seen more hours than this but I just don’t have a way to measure this.
The Aimpoint ML2 has a 10,000 hour battery life, (roughly one year). It has to be very close or over this mark. Given the fact it has stood up to every day patrol work, entry work, countless range days and tactical schools, on several different rifles, I would say Aimpoint is the only red dot optic I will ever use. If you purchase one of the newer Aimpoint models, (i.e. PRO, M3, ML3, M4, M4S, H1 or T1), with battery lives of 30,000 to 80,000 hours, these will likely last you a lifetime. There is no other optic that gives you this much bang for the buck.