I've been following BJDs for over a decade and sadly not got a single one yet
, it's kind of interesting when you think about how they evolved to having double joints and there's been trend returning to the single joint roots.
Being mostly a simple toyfag, I used to think that double joints are better because it means more articulation, but then I realize after reading and seeing how not fun/smooth to pose BJDs are, taking to account that their big scale doesn't allow them to interact with most toys and miniatures, I got to the conclusion that BJD first and foremost priority should be aesthetics, that just meant to be big beautiful dolls that you can't do much with.
My currently favorite doll body is the 1/4 Myou Doll, it's pear shape and got actual ball joints, it could use more defined detail in certain areas, notably the ankles and the bottom area looks kinda weird and have harsh sculpt to it. If this body was added more detail and sculpted more in the style of that big MSD DZ you posted, it would've been the prefect BJD body imho.