I had a Ric that had them as well. I'm certain neck through provides the aforementioned benefits, it's just something I've never really noticed in simple playing. My 'Birds don't have any noticeable dead spots, but most of my bolt-on's don't either. Do a real test and I don't doubt slightly longer sustain. Most seem to like neck through for sustain, but I hardly ever need a note to ring on that long and can always slightly hit the string if it is needed. In my experience, I've had dead spots on both kinds of construction, but expect sustain would be a little longer on neck-through, but it hasn't proven noticeable for me. Meaning, I've never had a note die out and thought, "If only I would and brought a neck-through bass." So I fully agree with you, but just haven't noticed much in terms of benefits showing up in actual playing. (It would also be impossible to say if a given bass would have fewer dead spots had it been a neck-through, or vise versa.) In theory it definitely should, but my Ric and yours indicates it's not a perfect way to eliminate them. Of course there are plenty other variables to be considered as well.