If you are predominantly composing music for the country / Nashville type sounding industry , you will get virtually no benefit from the Kronos in terms of better sounds for that genre . The pa4x beats the Kronos on virtually all natural accoustic sounds except perhaps some of the pianos and electric pianos but in the mix you won’t hear that . The Kronos does not have guitar mode or the tricks and articulations to make natural instruments sounds realistic .
I have to disagree with you on this... while Kronos does not have automatic DNC and you have to switch articulations by hand, the Kronos espescially in a studio can have some awesome acoustic instruments.. (even more so of you invest in some of the expansion packs) .. where it comes to to orchestral sounds.. the kronos by default blows my pa4x dead out of the water...
For realistic guitars and guitar strumming there are several specific Karma modes..so again your statement is jot entirely true, you can make very very realistic guitar tracks, but... thye do require more work then on the pa4x.
Again, archieving things on the Kronos takes more time then on the pa4x, a lot more time, but the results for any sound can be stellar..which includes all the country sounds one could immagine.
Where it comes to sound design on the kronos, its so deep that after all this time, as a casual musicians (2 hours a day) i still only have touched the surface.