Dave, you do remember that there are fingering tricks to mute style parts, at least in fingered mode. For example you can hit any three adjacent notes below the lh split and everything mutes except the drums.
Most of the drawbacks that bother you don't affect me. I actually prefer the ultralight (read flimsy if you want) keys.
Just easier on my aging wrists and fingers.
I think I would miss most of all the facility for so many foot controls, using the 6-button Korg controller and still have dedicated volume and damper pedals. . . and that wonderful Songbook.
I have also come to appreciate the individual fill buttons on Pa3X.
I WON'T miss the abrupt endings on many of the new Korg styles.
DonM