KETRON's approach is pretty unique and high tech... which does allow for Playback and Recording of the entire performance (including AUDIO DRUMS) onto the storage device! This means you can use a style that utilizes Audio drums, Audio bass and Audio Guitars, play along or sing as well and record everything to either a wave or MP3 file!

With the Audio elements being streamed from the hard/SS drive, very little memory is needed on board to process them.

As to the question of if you need Audio Drums or not, the answer lies in what you have and where you want to be with it. If a manufacturer has solid drum kit samples that can be triggered via midi to create a great drum set, then Audio drums are less likely to get them excited (but will still be a great add on of course) as compared to one whose midi drum kits are sub par ... adding Audio drums to such an instrument will really make it shine. Now consider having great midi drum kits PLUS Audio drums (like AUDYA/SD9), and you're in a class of your own.