Hi John,
glad to see you stuck with it. It's well worth the learning curve. It is a machine you can set up to suite your needs, just needs time to try & sort out how to do things.

The thing that had me most confused at first was the Saving/ Loading structure. In some ways it reminds me a tiny bit of the KN7, folder within a folder etc. Made it a priority after I accidently overwrote some styles I'd been working on for a week. Now I save everything on at least 2 usb sticks. Don't want to go thru that again.

I didn't really think they could improve on the PA800, but they did. I still have both.
A side by side comparison thru the same speaker system, the PA3X, just plain sounds better.
It's actually better laid out than the PA800. My 61 note keyboard is built like a tank. More compact & really solid.
It also has a set of half a dozen or so, sliders.
It's also great to have 4 fills instead of just the 2. It has the option of an auto fill mode, which works like the yammies, plus you also have 4 fill buttons ( & break of course).
For me the XG Drum Kits were a real bonus. I convert some of my yammie styles to korg manually. SAves me having to remap all the drums that weren't compatible with Korg.

I don't think you'd regret upgrading, but you'd still probably want to have a look at one first.