Vortex Optics SPARC Red Dot Sight Gen II - 2 MOA Dot

I've been running this optic on my AR-15 for over six months. I was previously running a 1-4X variable FFP scope, but after trying the SPARC I never went back. The optical clarity is excellent, it was easily zeroed at 50yds, and has maintained zero ever since. I've used it in a variety of lighting and weather conditions - dusk, dawn, bright sun, overcast, rain - with very consistent results. I can hold ~ 2 MOA at 50 yds with budget M855 ammo. My AR has an A2 front post, and I have the SPARC mounted for 1/3 co-witness. The only con (for me) is that the red dot won't stay on continuously and / or that it doesn't have a "shake awake" feature, but its price to performance value is high enough that I still give it 5 stars. No regrets buying and using the SPARC.