What I like is the consistency. Vigier have a very clever system where the graphite neck in half neck-thru so it stops just before the pickups. I think the key to a good graphite neck is first of all stability (not all I have tried or owned have been straight and I can't stand much neck relief) and the body wood character is even more critical than with a wooden neck, IME. Get the right wood on the right neck and the two resonate and work together beautifully.
There is no single best way of doing it and there are many good and bad necks, graphite or otherwise, and I think the neck itself is merely a part of the whole picture. As a sum of its parts, a graphite neck will enhance (or spoil) a bass depending on a whole host of other factors.
Cheers
ped