My thoughts on this subject:-
PA4X, great looking keyboard , nice keyboard feel, good sounds, has all functions I look for in arranger keyboard, separate buttons for break and fills, hold button, Restart button, after touch that allows you to bend the note without using joystick, the only thing that I like the least is Kong styles, I’m pretty sure it’s gotta be good, I just could not get into it, I really tried to , I had before Pa1x, 2x, pa900, the styles never really clicked with me.

Genos:-Styles and sounds are nice, it lacks dedicated Hold button, can not bend the note with after touch , no restart button

KETRON I don’t have SD9 had SD7 for a short period 1month, I like my Audya5 better other than nice Touch screen, KETRON has everything that I like as previously mentioned in Korg, big different is I’m used to hear Ketron styles

With all my rambling above, I’m most comfortable with KETRON