If closer to the eye you will see a bigger part of the target inside the red point "window" which might be better to adjust fast the point of aim/ forgot that there is even a black frame around the red dot window? At least this is the way I mount it on my rifles, typically for wildboar driven hunt and on my double. Have not tested the rmr, but from the docter/noblex, burris and leica, the leica red dot is far superior in optical quality (no reflection, no distorsion or color change)
Depending on your eyesight (e.g., astigmatism) you might see a star instead of a point/circle, which might be worst or better depending on the eye distance to the red dot.
it is a matter of personnal preference