Yes, I went from KN5000 to Yamaha PSR8000 because of the vocal harmonizer in the Yamaha. I think it was better than the "improved" VH they used in later models. It remained unchanged, as far as I can tell, until they finally addressed it in Tyros 4, which I feel is pretty good now.
DonM
Yes Don the VH in the technics units was terrible. I don't know why Yamaha wouldn't contract TC Helicon for their VH needs T4 included. Korg did it right.