Heavy speakers is a plus when moving low frequencies. Otherwise you have to strap or bolt them down and together.

_Might_ be the future of mids, but I doubt it. Advancement in ribbon speakers is more likely IMHO. Also people develop a taste for how some speakers sound. I don't see guitar music being played on anything too different for a while, unless it has the same sound character. Even if technically it's a better reproduction, it has to reproduce how paper cone speakers sound now better than paper does. Seems unlikely. To win, people have to like the new sound more, or not be able to tell the difference.