As a general rule of thumb, buying a new replacement keyboard when it comes out is usually disappointing when you get it, (After the short initial buzz) however if you skip a generation before changing, then that’s when it really comes together.
In the case of Korg PA, 1-3-5 or 2-4-6 (Although with the continuing demise of arranger keyboards there might not be a 6, but going from a 4 -5 will unlikely give you what you want, so get to know everything about what you already have)

Bill
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English Riviera:
Live entertainment, Real Ale, Great Scenery, Great Beaches, why would anyone want to live anywhere else (I�m definitely staying put).