From what I see it's not just the poly that's increased. Casio's sequencers were up to 10,000 notes and that has now increased to 12,000 notes. One thing that really has got my attention is that the specs say (without really going into detail) about creating styles. The info says "Rhythm Editor
10 user rhythms created by editing built-in rhythms". Perhaps they've added style recording to these models..?? The poly jump is a good move though.