It's common for people in these threads to advise people to try different BCs and a BP/W, and see what works for them. I'm not sure that's helpful. It's not like going into a store and trying on a pair of shoes. I hear that advice all the time, but I have yet to find a shop where you can really do that.
Of course, many stores rent BCs, but they are usually one style, and it's unlikely that you will be able to compare the best brands, styles or models that you are interested in. BP/Ws are virtually never rented, since they require adjustment to fit the diver. That's not a problem if you are buying a BC, but it's not so good if you are running a rental inventory.
Now does that mean that you shouldn't get a BP/W because you can't just pick one up off the rack in a store and jump in the water? Not at all. I really can't think of a single situation (apart from someone who needs a very light, rollup travel BC) where a BP/W isn't better (details above and elsewhere). As far as price, it's true that you can get a very cheap jacket BC for less than the cost of the cheapest BP/W, but that's comparing apples to oranges. A higher end jacket is similar in price. And since a BP/W is endlessly customizable as your diving changes, as well as extremely durable and modular (so you don't need to throw the whole thing out if, say, the bladder becomes unrepairable), it's not such an extravagance.
And of course any BC will "work", but that's not really the point of these forums. The idea is for people who have done a lot of diving to give new divers their opinions on optimal gear. If you are actually going to dive enough to buy your own gear, spending a fraction of the cost of a single week of a warm water dive vacation isn't unreasonable.