Former IX and X owner here.

It's wouldn't say the X is "softer." Let's just say that the X still rides "stiff" like an Evo should, but it does it "smoother" and with better damping/chassis stiffness than the VIII/IX.

On the NVH question, the X is quieter than the VIII/IX. Yet, it's still not a "quiet" car, so don't expect too much of an improvement.

 

Wow I didn't know that the 8/9 dont damp as well as the x. A friend of mine is thinking about getting a used 8 or 9 but he said riding in my x makes his "already bad" back worse ...