[Jim]

Well from experience, I have a Les Paul that has a set neck (actually I'm not sure of the difference between a set neck and a neck through-but it's one of those) and a strat that has a bolt-on neck. I'd have to say that the sustain is definitely superior on the Les Paul (but that is also because of the mahogany/maple body vs. the alder body - and it is also a lot heavier). Tone is more subjective. If I want a "fatter" tone, I go with the LP, but if I want a more clean "glassy" tone, I go with the strat. Neither tone is "better" IMO, they're just different.

Jim