I realize that as a fan of the jacket-style BC I may be in the minority here on SB. Maybe the difference between a back-inflate and a jacket-style is like the difference between a bare-bones 1960s Ferrari and a fully loaded old Cadillac. The back-inflate has everything you need for high performance and nothing you don't and, like the Ferrari, is fun for the enthusiast to drive and tinker with. In contrast, the jacket-style lets you lumber along in a carefree cocoon of comfort. I'm not interested in tech diving or configuring my BC to carry double tanks or anything special. I just want a comfortable, carefree Cadillac ride. I'm going to keep using my back-inflate for a travel BC, but prefer my old jacket-style BC for all-around use.
This entire post is, IMO, an excellent explanation for why some divers, in spite of knowing all the pros/cons etc, still choose jacket BCs...and why that's perfectly fine.
There are many divers who are passionate about their BP/W or back-inflation rig, and I feel that sometimes they are unwilling to accept that jacket-style BCs are just as valid a choice for some divers, in spite of their downsides. Too often, those who choose to dive jackets are assumed to be ill-informed, stubborn, or just plain foolish. I disagree.
I dive a back-inflaction BC. Not a BP/W - it's a BC, but it has an inflatable wing on the back of it, and that's all that inflates. I love it - I feel much more comfortable in it, and have no problems on the surface. I trained in a jacket, and the back-inflation BC took a little getting used to on the surface at first, but I had it down within a dive or two. I definitely am better able to maintain a horizontal position underwater, and I MUCH prefer the freedom in the front, which partly has to do with the fact that my boobs are left completely unfettered, as opposed to being squarshed in the jacket. (I realize this doesn't mean anything to the dudes, but I know plenty of female divers who feel the same way!)
My husband, on the other hand, has a traditional jacket BC - and it's a full-on jacket, with inflation completely surrounding him. He loves it, and has no interest in changing. He has no issues getting and staying horizontal. If he were to write up his reasons for sticking with it, they would probably sound much like Lorenzoid's.
So there you have it. Unless you have an intent to go in more of a tech direction (in which there are strong reasons to go with a BP/W rig), then I feel it's just personal preference. Try both, and see how they feel to you.