Woah. There's a bit of conjecture, huh!
I happen to aggree about the orchestral voices, but Yamaha is no slouch in the acoustic rhythm instruments section. There is also a huge advantage in the Tyros/psr lineup where drum sounds are concerned.(yeah, yeah.... more opinions). Many of my friends that heard the kn7k thought that the drums were less than stellar.

I'd rate drum tones in this order:
(not styles, just tones)

1)Ketron/Korg?Tyros
2)Roland VA/PSR/Gem
3)Technics/Casio/Farfisa

As for the styles themselves..... too subjective. Ketron, PA80, Tyros, VA7 all seem to be at the top of my list for groove and feel.

Tough subject - keep playing Jerry, and give us more input after you get your key-legs !