My Zeagle Scout is a back-inflate BC. I bought it rather than a BP/w as is it is very small, light, and flexible enough to take as carry-on luggage. I like it and I would buy another one without hesitation.
I chose a back-inflate BC mainly for the same reasons people choose BP/w - good trim in the water, less bulky, etc.. I found that some BCs which inflate on the sides as well constricted me too much.
The Scout will not maintain me floating face-up or upright if I am unconscious.
My Scout generates only 25 lbs lift, which is a bit on the low side if you are diving in very cold water with a 7mm wetsuit - don't get me wrong, it still works at depth to keep you neutrally buoyant, but you need to make sure that you are not over-weighted. It is fine for thinner suits and drysuits.