MJ,
The Korg keybed is stiffer and more expressive than the Yamaha PSR lineup ... even the Tyros line. This topic always ends badly, so I won't say if it's better or worse, but I WILL say that it's stiffer with a longer throw to the resting position. I am able to play more expressively on a Korg synth action. I don't use weighted action ever unless I'm on an acoustic instrument.