You know what?
I Thought about it, and the improvements I want in the sounds section, is just a very comprehensive set of sounds.
I want to be covered for any gig.
you enter to Yamaha\Korg\Roland product pages of their stage pianos\keyboard workstations, and they always writing "huge sound library for any musical style".
I have to say that almost all the patches on the PX-5S are good sounding, the harmonica is so so, the bagpipes is really bad, the clarinet is also so so, but that's all the bad sounds I can remember now.
but to be covered for any gig we need:
Tonewheel organ emulation.
Full set of orchestral sounds(many essential orchestral sound are missing in the PS-5S).
More variety of electric pianos.
Much bigger sound library that cover all the sounds you might need in the western popular genres.
And as I said earlier, keep the real sound design synth engine, this is a great synth, just make the option to build monophonic patches.
How much would I pay for the dream Casio?
If they will do what I ask, easely 2000$.
Really, there is no instrument on the market that do what I want and also portable, except for maybe Roland FA(not as portable as Casio), but Roland FA has to many disgusting and ridiculous sounds, really bad sounds, I much prefer the Casio sounds...