Some not-so-obvious benefits to rendering a gun DAO by bobbing the hammer, particularly on a lightly-sprung gun: Increased reliability and enhanced accuracy.
All else equal, a bobbed hammer is lighter, so it travels faster. It transfers the same amount of kinetic energy (it's the spring that supplies the energy), but in doing so faster, it imparts more power to the primer strike, and it's power, not energy, that lights off primers.
Also, the lighter hammer has less momentum. Momentum is what jars the muzzle upon hammer strike, so if your DA skills are good enough, you can enhance the accuracy of a DA revolver by bobbing the hammer.
A simple back-of-the envelope calculation tells me a 25% reduction in hammer mass leads to 16% more power and 13% less momentum*. That's a win-win in my book.
*and it may be even better in real life, since bobbing the hammer also moves the hammer's center of gravity closer to the hammer pivot, making the hammer travel even a bit faster.
