So, how do you really feel?
Look, the Sto-Fen is a simple diffuser, but doesn't do anything for refraction or reflection. It's been around for decades in one form or another (actually, that type of slip-on diffuser used to be included with many flash heads), and I can achieve the same results for free. I'm not against it at all, and if you like the results, great. Hey, I prefer Canon glass, and you may prefer Tamron. Same thing, just a matter of preference there.
My point was that I've just compared shots using naked flash in several direct and bounce configurations, the Sto-Fen, and the Lightsphere, and quite honestly, the LS kicks everything else's ass for the resulting image, short of moving up to more studio-appropriate equipment. Yeah, the price is absurd for what it is, but what isn't? The link I provided above shows that you can get either for a fraction of the "retail" price. What's to complain about?
As far as your doubts regarding the shots that GF has on his website, there's always the FTC if you believe it's a blatantly false or misleading representation. From my direct experience, it's pretty much spot on, even if he's about the most annoying, self-aggrandizing piece of puffery I've seen since
http://www.chadnelson.com/