Ian,
Let me correct you. The PSR-S500 replaces the PSR-1100 as stated on many web sites.

I hope the new Motif XS will inspire composers all over the world to produce better pieces of music. It sounds as if the XS could replace an entire orchestra. If only it didn't have so steep learning curve I might consider it for my classical type of music.

Donny, it is my feeling that tells me Yamaha is branching the PSR series into S series and E series. The latter have sliders and arpegiators which help produce very interesting pieces. Check it out PSR e403 demo

George