The folks at Invalid Link Removed claim that their synthetic material is better than wood for tone and sustain. They claim their bass has zero dead spots on the neck.
I'm fascinated by their instruments... forget neck-through, can you imagine the entire guitar made of a single-piece material? Of course, there's the price barrier again, so I don't actually have one.
If sustain mattered that much we would all be playing Kramer Aluminium neck-throughts from 1977 to today.
Dead spots. Sure I don't like them. But the instrument needs character, no?
Most guitarists and bassists want something interesting happening during that sustain, and take good things happening during the sustain over longer sustain.