(edited) People write about tone and people write about weight. We can all be clear that these are not the same thing. They may be associated in various ways at various times, but they are independent. Lower vs. high weight is clearly better and objective--we can control for weight and compare other things. Timbre/Tone is subjective and not as easily controlled. We can't take two basses with an identical timbre and then pick the lightest one (unless we are looking at units of the same model at
Sweetwater!). So the whole discussion is apples to oranges at some level. For a good sound, we want the least weight--an optimality problem. But there are so many varieties of 'good sound' that we are all looking for the lightest bass that has certain timbres/tones we are going after. So we will have to settle for optimal solutions within these subjective categories, and there will always be multiple solutions (i.e. local optima). What is the lightest bass that produces a great P-bass tone? Or, what is the lightest bass for metal? Most of us can't systematically try enough basses to answer that kind of question with much confidence, so we end up triangulating based on the few we can try. I gravitate without trying too hard toward the lighter basses I have that produce sounds I like--that's just a good compromise at best and everyone needs to make their own. (apologies if the previous unedited post seemed combative).