Maybe what Chris in VA meant also was that as these guns get smaller and lighter, the recoil makes good follow up shots almost impossible to do real quick. I experienced that myself with the XDS in .45.....darn thing flipped so bad it was 3-4 seconds between shots to get it all lined up again and do a reasonable group of shots. I fear that in a panic situation with something like that there would be bullets spraying everywhere.....
And that is exactly why I tell everyone that brings this subject up, the Glock 19 is the perfect carry gun, and I better preface that by saying IN MY OPINION. It's light, it's accurate, 2x the round holding capacity of these thin guns, it's bulletproof (gen 3) from a reliability standpoint, and follow up shots with it are a breeze even with stock Glock sights.