It also apparently takes significantly longer than just building with cinder block.

So, yah its interesting, and the rounded corner things, along with the hollow walls are "neat" but much of the cost of single story homes isn't the first story walls is it? Its all the finish work/etc that still will need to be done.

So, its hard to see where any cost savings can come from if they are optimizing a part of the design that contributes a minority to the total cost.