Tim,
Nice. Looks like Macassar ebony, right? Aside from the cost issues - ebony in general, and Macassar in particular, seem to be skyrocketing in price - I'd be a little concerned about the weight. Have you had an opportunity to compare neck dive with a comparable instrument with mostly maple neck? (probably not, and the fact that you have a chambered body would throw that off anyway).
'Nigel' - yes, I saw the reversed purpleheart you mentioned, though I'd been thinking about doing it with ebony before then. Maybe if I wait long enough, Rami will get around to trying one first and he can let us know how it turns out :-)
-Bob