Hello Sen,
I had seen them before.
http://johnlsayers.com/phpBB2/viewtopic ... 4999#14999
I'm not used to use those hangers.
Spoke once before about them.
I once compared them with traditional wool at a cavity applications for bas trapping purposes.
I should have to find old archives back for those hangers.
I still find it a bit strange why they work that well.
However the advantage was in favor of the wool on a cavity principle.
One however should be really carefull with those hangers. If they are far away from a reflecting backing (your ceiling) and those distances between them become relative large, they start working as baffle applications as you can see on the Sonex site.
Now typical for baffle applications is that they become BAD for low frequency absorption.
They start acting as absorption in a diffuse field, loosing the relationship with the controled reflection of waves against reflective boundaries.
Rougly one could say that a freehanging mineral wood board must be double as thick as the same board against a wall in order to show the same low frequent absorption.
Now, one can state: hé but this aren't baffels, because there is a reflective core in the center (wood, metal, whatever).
On my playing with baffels doc you see 2 times 2 measurements, one with and one without center core.
http://www.acoustics-noise.com/AFBsite1 ... affles.doc
This does not improve low frequent absorption as often is wrongly suggested.
You can also see that baffels as such are the worst way one can use absorption material for low frequent absorption.
What I'm saying is that the reason hangers work is more complicated, and is more related to the way they are positioned versus one another and de reflective boundaries than the hangers in itself.
Since this relationship is almost nowhere mathematically defined, I find it risky once you deviate from the proven exactly copied applications.
But the John Sayers site is more specialized in this type of application.
For me personally, I once left this approach (after studying it), and should need to completely refresh it to explain it better (for me personally it became mainly interesting as theory for the theory and curiosity, not anymore as practical application).
I want to say that this was and is still standard for many designers. So practice proofs that it works. But as you know judging a studio is often very subjective.
I assume Scott's suggestion for the huge SCA becomes more a suspended ceiling, with thick boards. I'm not sure anymore in how far those corner reasonings apply with those size ratios.
Also one should be careful with wool at a distance which becomes too large, since than the boards will start acting as in a free field (frequency dependent).
This means if one lowers a suspended ceiling, as such enlarging the cavity, the reasoning that low frequency absorption will continue to improve is wrong.
Once the diffuse field (reflections from multiple directions) become dominant or important versus the controled reflection behavior of the single reflective boundary, such boards start acting again as boards acting in a free field.
One must compensate that by thickening the boards (or putting a fluffier = cheaper) thick layer on top.
As a general rule: material free in space becomes less effective in the low frequencies, when it looses his relationship with the controlled reflection patterns in the vincinity of a reflective boundary.
The often heard approach that free hanging material can be striked by waves from different directions as such enlarging the useful absorption surface, which in its turn should relate in increased absorption is very questionable, and only valid when the edge effect (diffraction) becomes defining, which is not the case when freehanging objects are used in arrays.
Reflections can be compared with mirror sources. They exist always, whether the material hangs free in space or against a wall.
If that should not be the case, then a relative thin ceiling suspended at about ear height in a room (forget nodes antinodes here) should be superior in the low frequencies.
I can assure you it isn't, such an application will show a very poor low frequent behavior.
If the ceiling only must be functional, the cheapest manner to handle this is hanging a suspended ceiling profile system 600 x 600 mm = ca 2' x 2', putting additional wool on top, in which you can hang absorption tiles (making complete ceiling a bass trap), and substitute whereever needed, for reflection or diffusion, other tiles of whatever reflective or semi reflective board.
You can even hang diffusers in them.
Such an approach allows you to play with the tuning of the studio afterwards.
The advantage of reflective tiles is that they also act as diffuser (depending on sizes covered area), without or with limited effect on diminishing the bass trapping properties.
How would I incorporate them into those vaulted spaces? 
Sen, I'm Eric, Desart is a brand name (lots of them). Desart is used in formal circumstances and in informal circumstances mainly when I did something 
..I was just trying to illustrate the way I understood your explanation of the behaviour of those things in a given space...but of course....we still have the main walls 
...