Okay, here are the answers to Dan's questions.
First, I'd suggest reading the article about the SBS on OM; use the link provided by the OP; it explains the rationale and development of the design, and I think it's a pretty fair assessment of the design, and includes pros and cons at the end.
The SBS is certainly heavier than an equivalent Caldera Cone,and your guess of twice the material is about spot on. My Clone generator reports an area of 61416mm2 for a Titan kettle. This corresponds to 24.5g in 0.15mm Al foil. The equivalent SBS has an area of 2*12.5*60*(78+10)=132000mm2, corresponding to 53.5g in 0.15mm foil.
But the SBS was intended to overcome the storage problem of the Caldera; it will fit into the pot it supports. My home-made PET bottle caddy weighs 31g, bringing to total weight to 55.5g, so it's a toss-up which is lighter.
My measured values for Clone and SBS are 25g and 45g respectively.
When it comes to manufacturing, I fairly soon abandoned any plans to go commercial, which is why I'm offering the design on a MYOG thread. The amount of material used isn't straightforward (because the Clone isn't straight...). The SBS is made from a simple rectangular strip, so can have optimal use of the raw material. The Clone has curved edges, and so there is waste material between Clones. As a worst case, the xExtent and yExtent values for a Clone are 205 by 591mm, giving an area of 121155mm2 (cf 132000mm2 for the SBS). Of course, savings could be made by sensible tesselation of the patterns.
Now for the issue of stability. The SBS is contructed from a lot of triangular folds. They form triangular columns that are very robust, and very stable. For instance, take a look at the little 6g potstand in the OM article; that will support at least 3.6kg (that's when I stopped pressing; I didn't want to crush it). The sides don't bow out; that's part of the attraction of using folding to make a windshield (how the SBS came about). All those folds add great rigidity and strength, where a simple windshield would just flop about and fall over.
With sharp radius pots, such as the Titan kettle, the pot sits quite stably in the SBS, and you can happily rattle it about; I spent three days on the Alpkit coLAB stand demonstrating this to people.
Larger radius pots don't sit as well, as there's less of the fold to support them, so they're not suitable for use with the SBS. But then, not all pans are suitable for use with the Caldera.
The Caldera Cone is brilliant, which is why I Cloned it, (and later added the Flissure variant) and I'm not going to say that the SBS is better; it's just a different solution to the same problem, with different pros and cons. Everything involves some compromise, and the SBS compromises marginally on weight, whilst having a little more versatility over the pots that a particular SBS can be used with.
One other valid objection to the SBS is that it occupies the pan, and a lot of people like to store stuff in the pan; I can get the SBS, a burner and a lighter in the Titan, with a little room left to store small items. I know a lot of people put a little fuel bottle in the pot, but I prefer to keep methanol and Bitrex out of my cook pot.