It's a whole new world. As scutters said its Basically it's all about improving the audio of the tables. Alot of the older tables carry mono or crackly sound (think guns and Roses) pinsound is an external programme that you can use to take over the audio on certain tables and play remixed higher bit rate sound. You actually have an ability to do this nativity in visual pinball using the 'altsound' method (which you can google) but it doesnt provide the flexibility of pinsound, where you can Tweek the tracks and also load other non original tracks (i.e I have the new doctor who sound track on bally doctor who.). You can use both methods together to get the best experience. I use pinsound for cooler tracks,dr who, Indiana Jones, techno getaway and Addams f and I use the altsound method for some data east tables (which are known to be glitchy) and for some stuff that sounds the same... I've just gone through the pain if you need a hand. And scutters has been a great help!