Yes to all of the above. With music machine like ACDC it's much better to have music loud. But importantly, the quality of the sound is greatly enhances. It may just be the quality of the headphones vs normal pinball speakers, or that the mechanical sounds drown out some of the effect sounds, but the sound you get playing is greatly enhanced with the board/phones. You can still have sound on the machine too, or switch it off if you prefer. Not sure there would be such a great difference with other themed machines, but I'm putting one on LOTR so ill let you know.
