Well, I have only dived once in a jacket-style BCD, and I hated it, especially on the surface, and it didn't seem to fit, no matter what adjustments made. I dive with a BPW, and for a large person, back inflation is definitely a better idea. Another benefit is if you want to get into more technical diving, instead of buying a whole new BCD, you can just buy a different wing, or a different backplate. BPW also has much less drag than the BCD, and can be adjusted to exact fit. I found when I trained on a BPW belonging to my instructor (I and my dad were the only students) no adjustments were made to it after the initial sizing, and after two weeks (we expanded it to a 3 week course, part time) IT WAS MINE!!! It fit perfectly, and there were no problems. If ever you would have to make adjustments to your harness, the webbing creases, and reverting back to your fit is no problem. Also, I am not really a fan of the clik buckles on BCDs, and it is no problem to cut your harness in case of emergency evacuation. Also, there can be some problems with buoyancy in the BCD, (uneven air) whereas you can get a wing that is either a full air cavity, or divided compartments. I definitely think the BPW is much better!
Just my two euros.....