I have the ta44 acss and I'm a fan, but IMO you can't really go wrong with either, they are both solid performing optics.
I would give the edge to the ta44 because of the reticle being more than a dot has more uses like ranging a person or object, and that tiny bit of magnification is helpful at some distance.
Acog not perfect though there is issue with reticle visibility in certain lighting situations, IMO it's pretty minimal but happens. When you are in the dark looking into light, the acog reticle shows up a nice crisp black, but if it's shady, not dark and your looking into a brightly lit area the tritium can't properly light the reticle and the fiber optic doesn't gather enough light so you can loose the center of the reticle on lighter colors and mottled surfaces ex- off white stucco wall or a tan asphalt shingle roof. But you can still pick up the outer ring just fine so depending on distance your shooting it's not a major issue. I have a green ta44 so the red could show up better in those conditions