Be careful not to make the common mistake of thinking that the largest pistol you can comfortably carry is a sub-compact single-stack.
I'm still very new to CCW, but as I've compared specs between various guns, and looked at them at ranges or over counters, I've noticed that the single stacks of "normal" size (like G43, Shield, XDs, CW9 aren't
that much slimmer than the single stacks.
My XD Mod.2 subcompact is the same length and height as the XDs or Shield, and the difference in width is just a hair under 0.3". That may make some difference in concealment when looking in a mirror from 2' away, but I can't imagine it makes a lot of difference from a distance when you're just out and about. I think the flush magazines definitely help conceal better--grip length seems to matter more than either muzzle length or grip width.
I've thought about getting something smaller, and probably will. I shot a lot of the small single stacks just the other day and found the G43 and G42 (.380) to be impressively accurate pistols. Shield was real nice too, though I don't really like the curvature of the trigger. But in all cases it comes back to "Man I already laid out $500 for this subcompact double-stack, so am I really going to lay out another $300-$500 for a gun with less capacity just so I can shave 1/4 inch off the grip width???" Weight matters, sure--single stacks weigh less, and dropping 5+ rounds saves weight too, but with a good stiff belt (Bigfoot Gunbelts!!!!!!
) it doesn't make a lot of difference either.
For those reasons, I think I've decided that whatever I get next will have to be appreciably smaller than what I already have, and that means a G42/43 at the biggest--and probably smaller than that, which would be in LCP/CM9/Pico "pocket rocket" territory.
*** One thing to note, and this is just my very limited experience....
When trying out a "tuckable" holster, I have noticed that the single stacks do seem to be less visible overall. The double-stack grip can still be hidden under a tucked-in (not tight) button-down shirt, but on the whole, the rig leaves a noticeable lump under the belt. Single stacks in thin holsters definitely have less of that. I don't know if it's "printing" because it looks like a bulge and not a gun. But a pocket carry would solve that too.
So lastly, based on your list, my totally worthless opinion is that -- should you decide you prefer single stack guns -- I'd probably go with the Shield. I liked it the best of any that I've tried, just combining all factors (ergonomics, grip. weight, accuracy, etc.) The trigger could use some help but I'm sure I'd get used to it, like any. And I've often seen these guns on sale as low as $300 for the 9mm, which is lower than almost any other. I can't see how you can beat that. The G43 is a damn nice pistol, but is it $100-$150 nicer than the Shield? Not for me I guess.