An abundance of caution.

I'm with SLG on this one. I can't tell you how to butter your biscuits, but I personally would rather not carry a striker-fired pistol with no manual safety AIWB, other than a Glock with a Gadget. (And if it's a single action or striker-fired pistol with a manual safety, I'd only carry it in a holster designed to physically immobilize the safety while holstered.)

Tangentially related, I've been skeptical of pistols with striker-fired ignition systems and no hinge or tab on the trigger since the first popular models emerged, and despite having tried to make peace with the idea, it's just not working out well between me and them.

No one factor makes things "safe". There is no "perfectly safe". All we can do is stack slices of Safety Swiss Cheese atop each other in hopes of keeping the holes of disaster from lining up. You gotta decide how many slices you're comfortable with.

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