I dunno, looks to me like "the backup" option would always be catching your shins and getting smacked by the vacuum cleaner and such. Combined with the safety issue I'd not have it in my home.
Have a steel box with a simplex lock on it for my hot pistol. Primary home defense weapon is a Remington model 870 shotgun. Hangs up high and out of sight in the closet on a rack I made out of 2 pieces of half inch dowel mounted on a 1 x 4. Keep the action open with a cable lock run through it to keep the kids out of trouble, though all three of mine have had their share of range time and know how to handle a firearm safely.