Hi,
coming from a different angle.
Am I happy I upgraded from my psr s950 to sx900?
Hmmm. HELL YES!!

Personally I wouldn’t have necessarily done it just for a touch screen, but the added bonuses for me
The keybed, so much better than my s950
The chord looper, ( haven’t gotten round to working it out yet) but it will be something I use.
The overall sound is better than my s950.
Bunch of new styles ( May not be the case if upgrading from S970/s975) not familiar with those styles.
Scat voices. Ok didn’t think I’d have much use for them, till I started loading Tyros styles. A number of these styles never worked for me before, tracks missing voices. I couldn’t be bothered trying to revoice them, I was more wrapped up in my Korg. May well have been other types of voices missing too, but either way, I have a bunch of styles that I didn’t have before.