During the covid lockdown my piano went out of tune so I decided to have a look at the Kawai NV10S hybrid and Kawai CA99 digital just in case I find it difficult to find another tuner after my current tuner retires. The CA99 had a soundboard and I thought its sound and accompanying vibrations were very good. The action wasn't an acoustic action. The NV10s has a Kawai grand action which felt as it should. Its sound was made by speakers and it was this that didn't seem realistic to me. I tend to think that the sound would have been satisfactory if I had been using head phones. The other thing was that I tried these models in a dealership where pianos were closely packed so I may not have received a true impression.
Perhaps Kawai may install a soundboard on the next model of NV10S and then perhaps we would have a contender.