[aippi]

Shorter is better for HD use. That extra 1.5 inches is not an issue untill the last inch of it hits a corner of a wall as you try to turn to address a threat. Hall ways and doors are not friendly to long guns so having a long gun that is as compact as you can have is the best option.

I can not even try to come up with any scenerio in my home when a couple of shots will not eliminate a threat. With this said, the extra ammo is not essential to an HD weapon.
If there is ever a break down in civil order, I have other weapons that will move from the gun safe to my bedside.

You are right on track with what I tell my clients about using a shotgun for HD. You came to these conclusions based on your own expirience with your current weapon and should go with what you have decided to do.