What's The Point to an AR Pistol?

Someone posed this question to John Mosby recently and he addressed it in his most recent "Campfire Chat" column. He wrote:

      The point of AR “pistols” is, legitimately, the same point of a 10.5” or other SBR, without the $200 tax and permission slip from The Crown, honestly.

      You are losing some muzzle velocity, but you’re making up for it with handiness and light weight.

And, he notes, in a pistol configuration you don't have the interstate transportation headaches of a short barrel rifle (SBR). Mosby also notes that he has put a low power variable optic (LPVO) on his allowing him to use it out to 400 meters.

    The biggest selling point to me for an AR pistol was that I could keep it up in a shooting position and turn around in my house's hallway without dipping the barrel.