I don't mind a bigger dot on turkey guns and pistols. A 6moa dot will cover about 3" at 50yds. The bigger dot helps you get on it quickly opposes to a smaller finer dot.
Can't speak for the over under. I had read much of the same and got kinda spooked. If they don't shoot to a usable point of impact, 2 barrels are pretty well useless.
I went with the SA-20. Not sure if there's a way to reverse the safety. For the money, IMO, it can't be beat for a turkey gun. I like higher quality firearms but the better autos all have long barrels long LOP, no pistol grip options etc etc. I prefer a shorter barrel and a pistol grip on my turkey guns.