Jumping in here late, but the G19 is the ubiquitous choice for sure and is almost never wrong. I’ve never gotten along with the grip size as well as the G17, so it would be my choice.
Regarding small guns, I was shocked when I shot the IDPA classifier twice in a row and scored nearly identical with a G17 and a first gen Shield. I doubt the results would have been even close to the same had I used something smaller like an LCP.
The IDPA classifier is a pretty decent way to sort out how you are doing and it provides a useful benchmark to compare guns and gear with. It doesn’t stress capacity, otherwise the shield would have lagged pretty far behind.
