An overall opinion:
Tyros 4 sounds real good; styles and instrument sounds. They tend to be darker, more mellow – as someone said here, more like a CD.

The Korg sounds more realistic. I feel the Tyros 4 would be my choice for my home but mot for a job. The Korg being clearer and more realistic can be amplified strong and louder; which means more effective – better job sound.

IMHO, John C.

PS, I just read JG’s post; I guess he is right about who’s listening.