FWIW, the S&W "lemon squeezers" have an interesting double action mechanism in that as the trigger is pulled, there is a distinct hesitation point as the hammer reaches what would be (in an exposed hammer gun) the full cock position. At that point, the shooter may take time to aim the gun, then a short and fairly easy pull will fire it. Not quite as light a pull as the SA pull on a hammer model, but easy enough for aimed shots.
Jim