I have a Shield 9mm with a safety and a Shield 45 without. I like having the safety for times I may carry in a coat or cargo pocket without a holster. One thing I really have to credit S&W is the safety, very flush with the frame but when engaged I can sweep down with the side of my thumb knuckle to disengage, but for me it's VERY difficult to engage without using the tip of my thumb. The safety on my LC9S by comparison stuck out quite a bit more but was harder to disengage and easier to engage by accident.