Most people find larger dots (larger than 4 MOA) allow faster acquisition of the necessary visual cues at close ranges. For instance, the really fast Open Division shooters at the Steel Challenge will all use dots significantly larger than 4 MOA.
Keep in mind that the dots on Aimpoints are about as close to perfectly circular as you will find in the industry, with little or no "bloom" unless you turn the power higher than you need it. For that reason, they appear a little smaller than lesser competitors' products with the same spec for dot size. So, it's a little easier to use them precisely when you need to do so.
For instance, the 1 MOA dot in the middle of my EOTech reticle appears larger than the 2 MOA dot in an Aimpoint (to my eyes) because of the fuzziness around the outside of the dot (bloom). The Aimpoint dot is clearly defined and very easy to see and use.
Keep in mind that the dots on Aimpoints are about as close to perfectly circular as you will find in the industry, with little or no "bloom" unless you turn the power higher than you need it. For that reason, they appear a little smaller than lesser competitors' products with the same spec for dot size. So, it's a little easier to use them precisely when you need to do so.
For instance, the 1 MOA dot in the middle of my EOTech reticle appears larger than the 2 MOA dot in an Aimpoint (to my eyes) because of the fuzziness around the outside of the dot (bloom). The Aimpoint dot is clearly defined and very easy to see and use.
I've never used a 2 MOA, so I'm curious. If the 2 MOA is more accurate for longer distance, why would you want the 4MOA?
Is it just easy to see at 100 yards?
What would the difference be at, say, 25 yards?