Unlike Yamaha , Korg appear to bring out the Top of Line arranger first, then the mid level arranger a year or so later, wheras Yammie put NEW features into the mid level PSR's first, then bring out the top of the Line arranger.
TBH, I think the S950 is the FIRST MOTL Yamaha that had a significant feature BEFORE the Tyros... Usually, Yamaha introduce new stuff on the Tyros line, and it trickles down in 9 months to a year.
Or am I wrong?