To me the brilliance of the Facetmobile is that it makes us check our assumptions about the importance of curvy streamlined flight structures. As I understand things, the Reynolds number of a very deep wing like this is so low that making it smooth is much less important than our intuition may tell us. The issue that the Faucetmobile faces is the very high frontal area and sectional area. It's my understanding that the newer designs along the same lines are made with thinner wings to help reduce frontal and sectional area. The fact that it had a simple engine, and was puller rather than pusher, is easily explained by the fact that it was an experiment, and like any good experimenter, the inventor chose to use as much simple and known technology as possible, and reduce the number of variables. It's difficult to see how bound the experimental aircraft community is to the conventional cruciform layout, however a lot of people have died trying to fly, so it's not surprising that only a few people have the vision, and the knowledge to go outside the conventional box. My understanding is that most airfoils are as thick as they are, to allow the spar to be tall, and therefor stiffer and lighter. This of course has the downside of increased frontal area and sectional area. I'm wondering if a few sheets of aluminum, carefully cut like the origami boats, could create a very stiff upper wing structure, with no conventional spar, but with the loads carried in the wings skin.