You must admit he did well and I was at one time looking for that magic bullet. Easy prey I had two and gave them away after taking lighting courses.
My local photo store is where I took lighting courses won't stock GF products even though they know they will make money. They do not agree what the advertising states they can do. They never pushed products or told people not to use any. They would answer questions, give you the facts and let you decide. There should be more non commission sales mom and pop businesses.
One of the big chain photo stores in Canada showed before and after images of the Puffer on their site. After basically eliminated all shadows, even the shadow on the wall behind the subject. After about 4 months they replaced that a less drastic change between the two images. Still more of a shadow reduction than what I believe it's size and what physics tells us can accomplish but at least it was not so blatant.
I have long voiced my own complaint about the 'false advertising' bias of example photos posted on GF website as my primary complaint about the products. The products are not 'useless', they are useful and beneficial under the right circumstances; but they do not accomplish as much good as the example photos would lead the unknowing to believe. You don't need to spend so much money, to achieve the same end result.