If only one attacker an you get a well placed shot then game over for the SOB. But if you have multiple people coming at you and they are all armed then you better be able to get cover while reloading. I guarantee I can rack my slide faster then you can break your barrel and drop a shell and snap shut. Just silly to think other wise. Especially if I am half asleep. I am not going to fumble with a shell in the dark.
If I were a invader and was armed and my buddy was shot I would fight. Not run and get one in the back. i am just looking at the bigger picture. JMHO.
The OP didn't say a SS was his only option, but said in addition to pumps. He asked how others would set one up for HD, if it was all they had, not that it was all he had. Never hurts to have more than one option even if the fall backs aren't quite as good.