Unless you're looking to shoot tiny, tiny groups at distance (like it's going on a .22LR or a slim slide gun like a 1911 or CZ-75 that you're using for bullseye shooting), I'd go with the 6 MOA. That's still only 1.57" at 25 yards.
Everybody's eyes are different, but the 6 MOA dot on my EPS Carry looks cleaner/more defined than when I set my 507 Comp to 2 MOA dot only. Due to the extra smearing/comet tail that I get with my astigmatism, the 6 MOA dot isn't functionally 3 times bigger, it's more like 1.5-2x as big.