It's all training Buzz. From my military and Law enforcement training my trigger finger automatically goes along the fram rail and not onto the trigger until I am ready to fire. I have several firearms with external safeties, but I carried a glock on the job for 12 years, and now concealed, and would not carry it if it had an external safety.
If trained properly (and praticed) the trigger saftery is just as safe as any other weapon with an external safety. The department I worked for even dropped several glocks from helicopters at 500', and not once did they have a misfire.
