Gun Grape, here we have a duty of care, especially in domestic violence situations - this does not impose on us a duty to place ourselves at risk but it does obligate Police to act on DV reports irregardless of what the victim wants. Likewise with other crime types, we can't ignore/walk away from a crime in progress but have to respond in accordance to the SOP's for that crime type.
.... But back to the topic at hand - are "plastic/beanbag" non-lethal type shotgun rounds available for civilian use in the US market? (Havn't researched the topic but I suspect the answer is no.) If they are that might give SG's an advantage in home defence situations that would overide the benefits of a pistol. The first one or two rounds could be non-lethal with the rest conventional - just in case a particualrly stubborn/stupid intruder won't take "No" for an answer.