All I can tell you is that even with the smaller PA 500 that has the Style editing capacity to make from scratch styles that involves drum pattern creation and even more....you add all the wonderful sampling, editing, splicing that you can do on the PA3X....plus the powerful FX that has on the PA3x, I think the sky is the limit.
Now I understand the PA3X has not one, BUT TWO Guitar modes for style creation....awesome !!!
My friend Juan Miguel(PA800) and me with the PA500, created for Korg USA 32 Mexican/South-American ethnic styles,
I must tell you, of course, I did use software like any standard sequencer (an Old Cakewalk version I have), makes life easier and makes you work better.
Is amazing what you can do, like all that extensive editing I did with the PA500 for those styles, is like no other keyboard. It contains ALL the parameters, like a Chord Table Assignation Intro/ending in Mayor tonality and Minor Intro/Ending, each variation, Fill, etc.
For other brands, to make styles with "Factory" quality, is necessary a proprietary software that is only available to the style designers, not a need on the Korg's case.
I can not give my opinion on the sampler since I do not have one to play with.
There, my 2 cents.