I look forward to seeing the explanations. I bought Bottom
Line bobbin thread on the recommendation of several experienced quilters but I don't remember if they really explained why they use it. I do know that it is a much finer thread therefore there is more on the bobbin so it doesn't have to be changed as often. I would imagine with machine quilting that, because it is finer, it would show less on top if your tension isn't just right.
I have never tried one of the prewound bobbins so hope someone gives us some information on those--what kind of machines they work well with and don't work with. Any other benefits besides not having to wind bobbins.