Hi Steve, I now own my 3rd Pa4x, and a Yamaha Sx900. Your question is based on individual needs and desires.
Dave and the others offer good impute. Let me share you mine.

Pa4x: I have another pa4x for two reasons.
1-It is such a fantastic keyboard; it offers so much ---- for playing gigs!
2-Right now am using the Pa4x to save me from lock down; boredom.

I had a Tyros2 years ago. My all-time favorite was the Technics Kn7000, so you know where I am coming from. I owned the Korg pa800, Pa900, Pa1000, and the Pa4x. One thing I notice after buying a Sx900, is that most of my recordings/sequences were not done on my Korg keyboards; they were done with a Yamaha Psr2100, and a Tyros 2.

Yamaha has the most styles available, and the best support system. The instrument sounds are fantastic. Years aga they compared Yamaha’s sound like listening to a high-quality CD. I agree with that. The Sx900 is giving me a feeling to create. I do not get that same feeling with a Korg product. I no longer play out, so the next best thing is to create. (my opinion)

Prices: Buy a pre-owned keyboard from a reliable dealer, or someone you know. You get so much more for the same dollars. Buy with a return privilege.

Steve, if you were to post one of recordings/sequences, your question would be better answered. We need to know more about you.

Hope this opinion helps, John C.