Bachus

That is a good observation, and it hits home at the present. I, very foolishly, forgot to backup my USB card on the Pa4X and lost my Songbook registrations which numbered several hundred. Luckily, I have the same amount and similar songs on my SD40 and S970. Now, as you say, it is decision time.

SD40
Light, great sounding, and very versatile and could expand it's navigation a la Mason.
PA4X
My favorite for live play, plays CDG files, great editing, etc, etc. Maybe I could get someone to send me one of their keyboard sets and I could use it direct. Other than that, I am pretty much back to square one.
Yamaha S970
Like the SD40, it is loaded and ready to go. It is a great keyboard in the Yamaha tradition, and is used occasionally for more intimate gigs,

It was a bitter lesson learned when the USB stick died and retrieval doesn't look promising. I suspect I was hot swapping it, corrupting something.

Decisions decisions