Rammed earth also creates a monolithic wall, but it requires the use of very strong, rigid forms on both sides into which the soil is placed and compacted; Hyperadobe uses the tube netting as the form which is then incorporated into the wall itself and helps stabilize and reinforce it.
Cob needs to be thoroughly mixed with straw to help make it cohere as a solid, monolithic material, which is then placed on the wall in small increments (cobs) so as not to deform while it cures. Hyperadobe eliminates the need for the straw because the tubular netting holds it all together. This means that the wall can be built and solidly tamped immediately without the need to wait for the material to cure, and eliminates the time and labor consuming step of mixing the straw with the adobe soil.
Adobe blocks have to be individually manufactured in forms and dried in advance of being placed and mortared onto a wall. All of this is very labor and time intensive, and is completely eliminated with the Hyperadobe method.
Also with poly earthbags, it takes much longer for the fill material to dry out or cure, since it doesn't breathe nearly as readily. This means that the Hyperadobe walls can be plastered sooner and may not need the application of separate plaster mesh because the mesh is already covering the wall. Many plasters, especially earthen plasters will adhere much more readily to the exposed soil within the netting, making the wall even more monolithic.
Both HDPE and polypropylene materials have poor resistance to the UV from sunlight, and must be protected as much as possible against such exposure. However the HDPE netting would have some natural protection because it become partially embedded in the fill material when tamped. The more opaque the plastic is, the more resistant it will be to UV, so if there is a color choice, black is the best.
To further understand this exciting new building technology, I suggest checking out the Step-by-Step instructions provided by the inventor himself. This is from one of my other websites that focuses entirely on earthbag building.