Paul, mahogany does make for a darker, richer sound. I had the opprutunity to A/B two 5 String Mark Kings w/Bal. K bodies. One with maple/2 purple heart lams and the other with a neck recipe similar to Charles'. I preferred the maple neck as it makes for a brighter attack(which I like & prefer) but the mahogany based neck did sound excellent, very rich and full on the bottom and the mids and highs were smooooooth and buttery.
Gonna go play some Barry White now...ooooohh yaaa..