I agree that the Korg OS is deeper and more intricate than any other arranger. BUT... the price you pay is a formidable learning curve!

I've had and programmed some of the most complex synths and workstations ever made over the years, and I have to confess, the PA3x is right up there with the most difficult to fully understand and use. Simply the file structure is far more complex than necessary. As the OP points out, it is all too easy to delete work you have done and not know it, every separate element in the arranger has its own save screen and separate file structure. All well and good if you ARE a power user, but for the player coming from far less complex arrangers (particularly Roland and Yamaha), you are treading in a minefield at the start.

Personally, I prefer a far simpler structure... after all, why do we use arrangers in the first place? To make creating music live simpler! TBH, the idea of an arranger with the complexity of a full blown WS is a bit of an oxymoron!

IMO, the Korg's weakness (or strength, if you want power user flexibility!) is that each separate element can be saved independently. The voice edits can be saved as user voices, the style tweaks can be saved as user styles, multipads and samples, linked MP3's and SMF's, Songbook entries... all have a separate save structure. Roland don't use that. Everything gets saved to the one place, basically. This loses you a bit of flexibility. But it sure makes learning it all, saving it all (and not messing stuff up by accidentally overwriting a voice edit used in another song or style or performance, etc.!), and using it all a bit more intuitive.

Simple is good (up to a point!)