Haven't held either, but did look into them. Some issues people complained about that I came across while reading were:
Stoeger DD: No ejectors for the shells, making reloads slow having to pry the spent shells out. Also, the safety resets automatically after reloads.
Maverick Tac O/U: Major problem, especially on a gun sold as " tactical and home defense", is that they used a sporting type trigger that has this pendulum thing in the group that swings down and blocks it from firing when the gun is pointed down too far. So, if..say.. you're at the top of a flight of stairs and a bad-guy is coming up at you... your gun won't go bang if you point it down at an angle to take care of your problem. I wish I could find the thread I found about the trigger, the person even took it apart to show the pendulum blocking device in action. But if you are at the store handling one, ask the clerk if you can test it out.. point down 45 degrees and try to pull the trigger.. you will see. NOT something you want to find out in an emergency.
Found the thread, on the other forum I belong to, showing the trigger on the Maverick O/U.
So, out of the two.... I would stay far away from the Maverick and would have to choose the Stoeger.. that way I could at least shoot it when angled down.