To those who have actually owned a BK-9 and also a Korg PA900;
Which of the two keyboards sounds more realistic? I'm only interested in sounds, not features. I'm curious to know what the verdict is, especially important are acoustic (pianos, drums, bass, guitars, trumpets...) and orchestral (strings, woodwinds, brass and choir) sounds.

And I wonder if the new Korg PA4X will top them? From the few demoes so far, it sounds great.

Thanks for any opinions you'd like to share.