I'm just finishing a walnut guitar, it's currently strung up for a test fun proir to finishing. It's a bolt-on double cutaway, hardtail, double humbucker, with a maple neck and fretboard. 25.5 inch scale (647.7 mm), and the body is 1.75 inches(44.45mm) thick.
It's a very, very, clear tone. Defined, but not harsh at all. I think the maple adds some high-end snap to the walnuts low end, making a very balanced midrange machine, which is really a very proper guitar sound. It's a great jazz tone.
And it's so pretty. Like chocolate.