DGX BP & Wing: with or without STA?

[inquis]

What are people's objection to using an STA?

Moves weight rearward, making for a less stable system when horizontal, increases the vertical profile, additional expense and bulk in the suitcase.

 

[lexvil]

What are people's objection to using an STA?

For me none that aren’t far outweighed by the use.

 

[Scuba Scott]

Moves weight rearward, making for a less stable system when horizontal, increases the vertical profile, additional expense and bulk in the suitcase.

Those things are all true but the most important reason not to use one is most of the time you don't need one. Why use something that is unnecessary?
There really shouldn't need a pro/con argument. You either need it or you don't. If you need it, none of the cons matter.

 

[wetb4igetinthewater]

Moves weight rearward,

When you say rearword, do mean "towards the rear" (being serious)? Or towards the feet? As moving the center of mass towards the feet is

making for a less stable system when horizontal,

How so? From moving the center of mass a few millemeters towards the back? I would argue that the STA makes the cylinder more stable on one's back

increases the vertical profile,

By a few millimeters.

additional expense

Sure, but really cheap.

and bulk in the suitcase.

I take my BP/W apart, and the STA takes marginal space as it is when in the corner.

I like STA's as in my 5 mil, Deep 6 Eddy fins, SS BP & STA, I trim out nicely and am just heavy negative enough to maintain a safety stop with 500 psi in the tank. Now I like to shore dive in places like Maui, so I don't like to bother with renting extra lead. It actually saves me money, but then I'm being super cheap (and the Dutch side of my family is from a rather conservative part of the Netherlands: North Holland). But cost isn't the reason, convenience is.

The center of mass moves much farther back with steel doubles, so I don't see the center of mass moving far less in a single tank with STA to be an issue at all.

Just my perspective/perception. I'm not trying to invalidate what you stated, I just wanted to understand it. Maybe we are both right. Or maybe both wrong.

 

[Divin'Papaw]

Those things are all true but the most important reason not to use one is most of the time you don't need one. Why use something that is unnecessary?
There really shouldn't need a pro/con argument. You either need it or you don't. If you need it, none of the cons matter.

Scuba is an activity that requires a thousand choices. The only thing truly required is an air source and probably a mask so that you can see. Everything else is personal preference.

The same applies to an STA within the broader category of BP/W BCDs. Choice of wing, choice of plate, choice of harness, STA or not, where to put your weight, do you even use ditchable weight, etc, etc. A thousand choices. Every diver needs to figure out the right answers for themselves based upon their specific diving and their preferences.

 

[RIHappyDiver]

What are people's objection to using an STA?

Ultimately, my main objection is that with a 5 mm wetsuit, a steel 100 and my back plate, I would be overweighted. Beyond that, no objection. It just never was even a consideration because DGX said I wouldn’t need one, and nothing has ever happened to make me think that I should consider adding one.
In the end, if an STA works for someone then they should go for it.

Erik

 

[inquis]

Maybe we are both right. Or maybe both wrong.

I'd say both right. The downsides are small, as are the gains if you rarely need to swap plates, wings, or single/doubles. IMO, an STA is very valuable if you frequently need to do those things.