I prefer the BP/W.
Dove a Zeagle "Tech" for several years.
Now, unlike others, I don't place that much emphasis upon how the B/C or BP/W performs on the surface because I'm not there long. If I must do a long surface swim, I'll either snorkle or roll over on my back and comfortably fin my way out to the site.
Now, having said that, when wearing a lot of neoprene, a back inflation B/C has a greater tendency to put you in more of a face forward/down position at the surface.
Why? At the surface you are trying to be in a vertical position. Your gear/body configuration becomes something akin to a lever with your body as the fulcrum. One force, the B/C is pushing up on one side of your body (the back) while the other force, your weights, are pushing down on your front side (just so happens to be where one's face is located on most human beings).
The reason this happens is that it is difficult, if not impossible in some cases, to position the required weight in the proper position on the waist, or in the B/C's pockets, if it's weight intergrated, in order to effect a comfortable vertical position at the surface.
The more the B/C is inflated, the more the face forward/down will be emphasized.
The BP/Wing, however, takes much of the weight and places it on the same side as the bladder, reducing the face forward/down result.
Also, with the BP/W, when weight is required, I can position all of it aft of the vertical centerline of my body, that is, positioned somewhere around the kidney area. The positioning of weighting in this manner keep the counter forces on the same side of the body and allows one's exposure protection, wet or dry suit, to add positive buoyancy to the front side of the body, thus eliminating any face forward/down effect.
So, that's why I like the BP/W.
the K