I might be wrong but I have found multiple light weight bolt on guitars that sustain for ages which is opposite the implication that neck through construction and heavy guitars have substantial amounts of sustain. So does a well made bolt on increase rigidity of a given platform over the same guitar made with a neck that is incorporated into the construction? Also in the case of archtops does it noticeably affect sustain in where the neck and top join? Acoustic resonance changes to my ears aswell as the feel between a guitar where the neck is fully joined to termination as opposed to joining then having the upper fret portion removed from the body. I have never noticed a sustain difference between those two methods of joining a neck to a body. Bigsby vs stop tail is tremendously noticeable but for much of the style of music produced with a bigsby mounted guitar long sustain is less desirable Bracing style in a given semi hollow no matter the method of string termination affects sustain substantially. A hollow with enough bracing to safely mount the stop tail but nothing further sustains substantially less than a 335 style full on center block that bisects the chamber. What is the honest to goodness difference between resonance and sustain? It seems to me that the two concepts collide and yet are at odds with one and other.