It's the samples, pure and simple. Yamaha have always done an exceptional job of recording samples for keyboards, possibly to do with them actually MAKING the real instruments in the first place, so a bad sample quickly gets shot down for being wrong!

This is superb, if this is the kind of thing you are into. Short of some VSTi libraries and a few Akai loads, I don't think I've heard better orchestral samples, especially out of just the one machine. I've always had to do it from a combination of different things... this one's strings, that one's flutes, this oboe, that french horn, etc.

The thing is, the all blend together very well. A bit 'distant', if you will, though. Very much a large film orchestra, on a large stage, rather than a more close and intimate smaller ensemble. But it's too much to expect EVERYTHING..! If you like this kind of sound (and who doesn't!) it looks like the easiest way to go, short of a decent VSTi rig and something like Vienna Orchestral Library...

Just remember, the samples are just the START... When it comes to orchestration, it is still 90% what you play, and how you play it, voice it, orchestrate it. There's no easy OOTB solution. You still have to play great!