Do you have a holster for that 22LR rifle, or is that a 22LR pistol? Are you suggesting that a S&W M&P 15-22 is as mean as it looks? More ammo for Pelosi, et al.... ;>)
One has to know which weapon to use - (and when).
Smith & Wesson is definitely a mean looking pistol, no doubt.
Ease of use in a variety of situations and environments does not make it the ideal self defense weapon.
Think of actual environmental situations and vary your source(s) of defense accordingly.
Not all of your needs for self defense are limited to the interior of your house or from the interior of your vehicle.
Additional note.
a good shiv is also a necessary and time and situation may save your life in times when other weponos are not quite as effective. I carry one plus a Swiss Army knife AND a toolman.