Oh boy, you just opened a can of worms. These threads tend to explode.
There are many many threads already beating this subject to death. Do a search then commit to about a weeks worth of time straight to get through them.
But if you want my opinion, yes they are worth it and the only way to go, IMO.
There are many people on this board, people working in dive shops, gear manufacturers, etc., that will tell you contrary, and there are a lot of BP/W people here that are totally pro BP/W.
I am a minimalist and don't believe in a lot of fluff in dive gear. I like very simple streamlined gear and a plate and wing is about as basic and functional as you can get.
My suggestion would be to buy a BP/W first and use it, then borrow or rent a jacket style BC and see the difference. If you like the plate/wing you haven't lost anything. If you like the jacket BC it's easier to sell a BP/W then it is a jacket and the resale is better. BP/W are in very high demand.
Also, those "hybrid" back inflate BC's that kind of look like a jacket but don't have any inflation on the sides but still have all the sewn and padded crap everywhere and integrated weights, those don't count as a BP/W's.