These Kiwame resistors are expensive only because audiophools are ready to pay a premium for glorified cosmetics.
They probably "sound" different, just like two resistors of different size, material, construction or coating sound different. Being carbon-based they have probably a higher R vs. V variation than metal. This is probably why they claim "more natural sound". It is well known that more distortion means more natural.
However, considering the extremely low power they are submitted to - in the order of a fraction of mW - I don't doubt it is minimal.
Finally, I must say I'm impressed with their claim of "Extensive neutrality". These guys are creative. What about "unstoppable transparency", or "radical naturalness"?