I'm new to this board, and relatively new to diving as well, and I've been wondering for a while what the whole deal with women's BCDs is, anyways? I'm about 5'7" and...well, quite definitely *not* built like a man, and so far I've only ever used unisex jacket style BCDs of the Mares/Dacor/Beauchat kinds. For me, as long as I can get an XS (ie: the rental counter isn't out of them, I've not got someone that's eyeballing me and thinking "medium", and/or I'm not wearing a particularly thick wetsuit (or clothing in the shop) making me a bit less flexible), they've been great, never even noticed problems with the chest straps I've heard some women elsewhere complain about (in fact I prefer them since that's one more place to hang things).
A small will do, if I can get myself in my preferred position to put it on and adjust it rather than someone else in a hurry trying to "help" me with it and then toss me in the water with nothing tightened the way I like it, but the mediums just don't fit, particularly as I'm more than a bit of a floater and need as little inherent buoyancy as possible to avoid having to wear 20+ lbs of lead in tropical waters. I have no idea why some people eyeball me as taking an XS and others a medium, but nobody ever thinks I could be in between and hands me a small right off, but...
Do the problems with unisex BCDs tend to pop up mostly in the weight integrated designs (which I've never used)? Do women's BCDs have less inherent buoyancy than similar men's ones? Cause it sure doesn't look like it's a color thing... ;-)