"Run and Gun" Fantasy or Practical?

You say "no politics" but your question REEKS of politics. There have been documented cases of shootouts, some of them FBI, where the "good guys" were outgunned.

You don't prepare for the best, or the average. You prepare for the worst. It's OK to hope for the best.

I'd say that in "most" situations the Great Big Barrel of ANY shotgun is going to impress, and it is a CERTAINTY that the distinct sound of a pump being cycled is going to make even the most drug infested douchebag start to engage the two brain cells he has left. Around here, hunting shotguns are limited to 3 rounds. Only three is not what I want in that late night, bleary eyed encounter.