I carry my .40 exclusively in single action. I have small hands, so I find the safety hard to disengage with my right thumb (I am right handed). A simple solution to this is to use your left thumb to flip the safety lever down, which is what I do 90 percent of the time. I wish the safety lever was a little farther back and stuck out a little farther, but it hasn't kept me from carrying cocked and locked. I feel perfectly safe/competent doing so because I practice with my weapon.