Mine has the thumb safety and I like it for certain situations. I always flip off a thumb safety when I draw (even an imaginary one
. Raking my thumb down the frame and slide is just part of me lining up a shot.
So, I carry the Shield with the safety off in its holster. Because I have to secure my gun in my truck often and the holster I use is a bit loose fitting unless tucked to the body (the gun readily shakes out), I often draw the gun carefully, engage the safety, and secure it in the nano vault i have. It won't fit inside the holster, but it keeps handling the gun in tighter quarters a little safer.
I also use it when i travel. I prefer to have my pistol at the ready, so I keep it by the bed with the safety on.
I dont prefer a safety on a duty size polymer pistol like a Glock or 320, but those little guns have all their parts and piece and triggers close at your fingers. The shorter muzzle makes it easier to sweep yourself or others. If I have to handle them outside of their holsters, having a safety isn't a bad thing for me.