The negative is having an extreme off-centre of gravity.
But you don't have to have an extreme off-center COG, even with a BP/W.
Sure, using a steel tank on a weighted STA on a steel plate and the weights on your belt pushed around to the small of your back will make you top-heavy when you trim out horizontal. But move those belt weights around to the edges of your hipbone and put a couple of weight pockets on your waistband, and you trim out beautifully. Even with lots of weight and a DS with winter undergarments.
Sure, on the surface you need a couple of dives to get used to having your buoyancy on your back. But as soon as you learn that lying on your back is the preferred option anyway, that issue, too, is moot.
Disclaimer: I'm using the generic "you", not the personal "you"
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