IMO, the reasoning in this comment sort of stumbles over itself a few times. You allude to the realities of typical self defense encounters ( very quick with limited shots fired, usually cited as averaging just shy of 3 rounds, IIRC), but then take issue with supposed "limited capacity" of the Shield.
The 9 rounds of 124gr +P HST's that are in my Shield more than triple the statistical amount of ammo fired in an armed confrontation (again, IIRC).
In a situation that is as "quick,close and reactively dynamic" as you describe, and one that is too close and brief for spare mag reloads to be beneficial, how exactly is 9 rounds insufficient?