The first centerfire handgun I got to shoot was my Grandad's WW1 1911 when I was 12.
I shot them in the Army and have carried them continuously for the last 40 years. Something comforting about the bigger bore.
So I'm pretty much a .45 guy. I've had a couple 9mm's, but was never too excited about them.
After having all three calibers of the Shield, and putting a few hundred rounds through each, the 9mm would be my first choice, had it not been for the PC .40 Shield I bought first.
The recoil of that ported .40 is, to me, closer to the 9mm than the .45.
My PC .40 has a great trigger, and the size is the same as the 9mm Shield. And last year I picked up an FDE FS M&P in .40, so I can consolidate on ammo.
My .45 Shield was more accurate at longer ranges, like 25 yards plus, but at more reasonable Shield ranges, 7 and 15 yards, all three calibers were about equal.
I do like the better stippling and more positive safety on the .45.
The size of the .45 isn't bad, just isn't as small as the 9mm/.40.
The extra length in the grip of the .45 does make the grip with the short magazine nice. And the longer mag for the .45 doesn't have that goofy sliding spacer like the 9mm/.40.
I do shoot the 9mm better ( or the ported .40) better than the .45.
Quicker to get back on target, cheap ammo for lots of practice, a bit more concealable than the .45, and with a good round like the heavier HST's, something I would feel comfortable with.
I'm giving the 9mm Shield to my daughter, and almost hate to part with it, as I like it.
But I'm happy with the PC.40.
I have come to prefer the shorter magazines for any of the Shield's with the Pierce pinky extension installed. The bright Aqua blue holster and mag pouches for the 9mm were my daughter's choice.