Good essay.
I tend to agree & think there is no "best" per se, but what you have handy when the balloon goes up and hopefully some training to go with it... also, that everything is a compromise of one sort or another, be it where you live, round (cartridge/shell) chosen, weapon in hand, amount of training, layers of defense, dogs, alarms, what-have-you.
To subdue the enemy without fighting is the acme of skill.
So the best might be the one you did not have to use... because if you did use something (whatever you had at hand, say) once the dust settles and the smoke clears, I'd think one might reconsider their choice for the next go round and add more power to the equation, as in the old axiom, "once bitten twice shy" school of thought.
While I enjoy reading the "Armed Citizen" in the American Rifleman every month, I often wonder if any of the good guy victims would, after the fact, consider using the same tools again or if they now felt the need for "more" in their search for the "best" gun for defense? Of course, not all of them actually had to shoot their bad guys (see above Sun Tzu quote), so, maybe 50/50. Dunno.
Always enjoy a good "Which is best" thread? This thread and all the responses are actually quite good. Kind of a THR trait one would suppose.