Aimpoint pro has a great battery life, but the M4/M4S has it beat, but also 2x the price.. lol But the most important part IMO is that an Aimpoint can go through hell and back and still function properly and hold 0. Same can't be said for the cheaper end optics. My Aimpoint pro has a battery life of 30,000 hrs which is 3 years on setting 7. Highest brightness setting is 9. My Aimpoint Comp M4s has a battery life of 80,000 hours/8 years if left on. My Vortex Sparc has the auto shut down feature which turns off the optic in 5 hours, but on highest setting, the battery life is 120hrs. 3500hrs on the dimmest.
BTW E, it looks good. Now it just needs a supressor.