Generally, I’d say choose the largest capacity pistol in the the largest caliber you shoot well...
But there is a good case to be made for the 9mm...
Without starting a “Mine’s bigger or better” war, take a look here: http://www.tactical-life.com/firearms/7-reasons-cops-choose-9mm-40/
I carry a 9mm daily and have never felt under-gunned...
“To each his own”...
Agree on all points you made in your post. My current caliber / capacity is a Glock 31 ..... meets my local needs for my local threat with the 125gr Gold Dot HP’s from Speer .....
Stay Safe !
FBI is going back to 9mm. I carry Hornady critical defense.
“I carry a 9mm daily and have never felt under-gunned...”
Not to be too picky, but any handgun you can carry concealed is under-gunned.