I'm accustomed to thumb safeties on semi-auto pistols after decades of having them on pistols. Flicking my thumb down over a safety is as natural a movement to me as pulling the trigger.

I carried a Glock 30S concealed for almost a year. Even after that time, having it holstered with one in the chamber but no thumb safety still made me a bit antsy.

So when I bought a Shield .45, I bought one with the manual safety. It's now my carry pistol.