Mike thank you for clearing that up with your reply on the G70.
Sounds like 256 poly is a must for you .....do you create complex arrangements? If so why not forget an arranger and continue being happy playing synths like the ones you have or Kronos, Motif etc,.. which for your needs seems to be better equipped in many ways vs an arranger. Everyone has different needs when choosing an instrument....bottom line is producing great music there are no rules ..

Good Luck