Decent quality and specs - Burris FastFire AR-F3 Flattop Sight

For the price I paid, I'm fairly happy with this red dot. The 3 MOA dot however is not super crisp, there is a slight blurriness or starshot around the dot. I owned an Aimpoint PRO before this and that 2 MOA dot was crisp and fine. That is a much more expensive red dot of course and the difference is price is substantial for some folks. I only sold my PRO because it was too bulky for my SBR. The spare battery compartment is actually under the optic in the AR-F3 mount. I don't think that's very convenient as you have to remove the optic but it is keyed so in theory you won't lose your zero or much at least. Overall, the Fastfire is a nice red dot far as features and size.