I dive a BP/W and wetsuit because that is what I am most comfortable with doing. Trim is a lot easier than with a jacket style BC. I can setup the BP/W with D rings where I want them and not where a manufacturer has placed them. I can use the same setup for technical or rec diving just by changing the wing. A dual bladder tech wing provides redundancy with lift. Diving in a wetsuit here in the Florida caves is not bad now that I no longer do anything longer than mild deco dives. Now having said all that, I find myself jumping down the sidemount rabbit hole with a new Katana 2 dual bladder, so we will see how that goes. I guess what I am saying as others have said is that you find a safe rig that works for you and dive with it. Of course getting to that point can be $$$$ and filled with false trails. Be safe.
Going sidemount (congrats I hope you'll love it), you'll see that most bladders are shaped like triangles: a lot of lift at the lower back, almost nothing at the upper back. Makes a lot of sense to me. There's no advantage in adding lift at your shoulders/neck unless you carry a lot of gas on your upper back like with backmount doubles. When I wrote that above I thought about a single tank thick wetsuit diver, who doesn't need lift at his upper back either, but a lot at the center and lower back, that's why I'd say jacket bladders are tailored to this kind of customer needs, most BP/W wings are not. BTW, better stay away from dual-use (backmount+sidemount) setups, they're not optimal for either also for that reason (sub-optimal bladder shape).