The key to any discussion of home defense weapon selection is to decide what is more important to you:
1. Ready access and convenience
2. Power and accuracy
Since just displaying a gun ends over 90% of confrontations and having a gun is an essential element of surviving a violent encounter, I tend to favor ready access and convenience - which usually means a handgun. The problem is that many people are not willing to actually carry the handgun and lose the major benefits it offers for home defense. They find the idea of carrying a handgun in their own home silly - so at that point, the only thing the handgun has left is convenience - it can be carried and operated one handed. If you can't get around that mental block, you might be better off with a long gun that has better power and accuracy and a long gun in the closet is just as accessible as a handgun in the night stand drawer.
Of course, the ideal solution is to carry a handgun and have a long gun stored in the house, as well as the training to use both of them; but that is not a cheap solution.