I carry mine cocked and locked, like I carry a 1911. Been doing it so long that's just the best way for me.
The B models with a thumb safety also have the firing pin block (what the "B" stands for - block). It blocks forward movement of the firing pin unless the trigger is pulled. So even if the hammer were to fall (while the trigger was NOT being pulled) the pistol should not fire. Even if it was dropped from some height on it's muzzle, inertia could not cause the firing pin to move forward against the firing pin return spring and make the pistol fire.
I never carry a pistol with an empty chamber. You may not have time to rack the slide to the rear. You many not be physically able (only able to use one hand, for some reason - injury? trying to keep someone from grabbing your gun? carrying/dragging an injured person? who knows.)