The walnut family of woods are a woodworkers dream, beautiful to work with and aesthetically striking. The particular species, Claro Walnut, also sometimes referred to as California Walnut or Oregon Walnut, also makes for a fantastic tonewood. Its mass and density certainly tips it towards a more fundamental response when compared to something like rosewood, the overtone content is not as present. Walnut is often described as having a 'dry' sound as a result. This isn't 'good' or 'bad', it is its own sound, its own tonal flavour.
This set is ear marked for a trade with Maegen Wells in California, I expect it'll make a fine Model S and the set is even big enough to yield a soundboard to match.