Diki,
There's room for both.
There is always the folks that just want a simple MOTL arranger that is easy, and does not have all the bells & whistles. You just turn it on and play some music. This is where Yamaha shines IMHO. Get a S900(910) and be done with it.

Then there is folks like me...I want TOTL sound, functions, MIDI impementation, VP, editing sampling, expandability etc.

Actually the Korg PA2 is pretty close (like James also said) ...but there is some work to be done. Don't get me started! :-)

Lee S.