It is better than some, not as good as others. I would say that it has better sustain than most of the basses with a maple-only neck recipe. If anything, it's maybe a little bit naturally bassy. I was wrong about the wood recipe, by the way, the wings are solid flamed maple (mine is less figured than others I have seen). It looks like a five piece neck of maple with a couple walnut stringers. The body also has a pair of similarly sized pieces of walnut separating the neck from the wings. I can practice with songs coming from laptop speakers unamplified. The bass can be heard in the next room when played without an amp. Not loud, but you can identify the notes.
Also, I have the 2nd generation model which only has four knob electronics. The originals had five. I guess this model doesn't get EMW, it would have to settle for Spoiler or Orion guts. Or maybe some sort of hybrid Signature without Q switches.