I have one and it sucks. While it is more omnidirectional than most standard antennas, it seems to have a far lower gain. For example in Queens NY, a cheap $5 antenna (basic rabbit ears) would pickup more stations than the mohu leaf, though I had to position it carefully for different stations. The mohu leaf picks up far fewer stations but for the one it does pick up, one position can usually pick up most of them.
The build material is pretty much the same as those really cheap laminated table mats. Inside is a thin metallic foil cut into a certain shape (essentially die cut foil)
The actual build cost must have beenaround $1 or less.
Since I bought it directly from them, their return policy makes it hard to get a refund. At the time they wanted a large restocking fee in addition to having to cover shipping cost. This business model allows them to sell ineffective antennas that do not come even close to meeting the advertised range, and for the people who end up with it, will be disappointed and have to choose between keeping it an hope to find a use (for me, it works well with software defined radios), or try to return it and essentially only get a partial refund (essentially giving mohu free money as they keep some of the money and get the product back to resell to another person who may then also return it. with enough work on mohu's part, they can essentially sell the same antenna to many different people.