I bought a BP/W as soon as I finished OW training, just over 1.5 years ago. Now, I own 3 back plates (2 x SS, 1 x Kydex) and 5 wings (2 x single tank, 3 x double tank).
These are the negatives that I see:
- None of my rigs live up to the promise of easy to adjust the fit and one fit working for all dives. I have found that they only work their best when they are sized just right. And my setup for using with a 3mm wetsuit needs to be a different size than my setup for use with a dry suit and undies for 38 degrees F water. Adjusting the size means moving 4 d-rings around and changing the length of the shoulder straps and the length of the crotch strap. The webbing is stiff. The rubber grommets in the holes of my DSS back plate grip the webbing. Adjusting it is a pain. The upside is, once it's adjusted to the correct fit, it is awesome and I don't ever have to mess with it. It goes on and off totally easily, even in the water, without any quick release doodads or cinch slide thingies or whatever.
- "Buy one rig for all your future diving" also hasn't really held up to its promise. A SS back plate is too heavy for some dive scenarios. Not unusably heavy, but heavy enough that some scenarios make you want to get an aluminum or plastic back plate. And if you just go with a light BP to start with, you don't have that problem, but then you lose one of the big benefits of a BP, which is having a good chunk of your ballast evenly distributed across your back, instead of in pouches or pockets or a separate belt somewhere. If you always just do one kind of diving - say warm water, single aluminum tank, then you can just buy one setup and it will always work for you. But, if you use steel or aluminum tanks and dive warm or cold water, then you end up (like I did) finding that one rig doesn't really satisfy all your diving desires.
- It's a lot easier, if you're doing it on your own, to get an integrated BCD that is the right size for you, and fit it to yourself correctly, versus if you buy a BP/W and fit it to yourself using online pictures and instructions. The right size integrated BCD will fit you just as well as a BP/W - and why do you really care if the BP/W could be more easily fit to a bunch of different-sized people? You only need it to fit you, right?
- If you decide to buy a lightweight BP/W for travel, that might be all you need. But, if you want something, say, for colder water, near home, you could easily end up wanting to buy a heavier BP, and possibly a wing with more lift capacity. At which point, have you saved yourself any money or hassle over just buying an integrated BCD that would work for both? An integrated BCD won't work AS well in any given situation as a properly chosen BP/W. But, good quality integrated BCDs are still pretty darn good. As one anecdote, I got my first BP/W (a DSS - so very good quality) from a guy who bought it brand new, used it for one week on a trip to somewhere in the Caribbean, then came home and stuck it in a closet and went back to using an integrated BCD because he liked it better and found it more convenient. "Everyone" on ScubaBoard loves BP/W. But, not everyone in the real world likes them best.
- No, not all BP/W rigs work for single and double tank. All BPs work for double tanks. Some do not have slots for tank straps and so they require an STA (Single Tank Adapter - $25 from Dive Gear Express) to use with single tanks. Most have the slots, though. Wings are generally specific to single or double tanks. There are a few wings that claim to be for single or double tank use. I have one of those and it works well for double tanks, but I wouldn't use it with a single tank. It's too big.
Getting an integrated BCD and then, later, if you develop a need, a BP/W with a double tank wing, is a perfectly valid approach. Just because you go to doubles and start using a BP with a double tank wing does not mean you have to also use a BP/W for single tank. And, based on what it seems that most people do when they go to doubles (i.e. end up with separate BPs and Ws for single vs doubles), you potentially will still spend less money.
To further illustrate the Dark Path, I don't have so many BPs and wings for no reason at all.
The Kydex BP is for warm water diving with steel tanks (singles or doubles).
One SS BP is for warm water diving with single aluminum tanks and cooler water with steel tanks (singles or doubles), in a wetsuit.
The other SS BP is for cold water, where I am wearing a dry suit.
One singles wing (23# lift) is for warm water. The other (30#) is for diving in cooler water where I need more lift capacity because I'm wearing a more buoyant wetsuit.
One doubles wing (45#) is for warmer water, with doubles. The other is for colder water with doubles where, again, I need more lift because I'm wearing an even more buoyant wetsuit or a dry suit. The third doubles wing is for sale.
A good integrated BCD would likely serve you well for all single tank diving, from board shorts in the Caribbean to a dry suit in the Great Lakes. It would fit well and quickly and easily adjust from board shorts to a dry suit. If it has enough lift to use with a dry suit, it won't be as streamlined in warm water as a BP/W with a small warm-water-sized wing. But you probably won't ever miss the difference.
