Gimmick? Yes, based on the re-activation thing and the ad saying forget the wind. But I do think the main thing that turns people off about it, could very well be the one thing that actually helps to some degree. It's the fact that the garment does NOT breath well. In other words, it contains much of your scent because it doesn't breath well. You just have to know how to use it (like putting it on AFTER you arrive at your hunting location). Obviously, it's worthless for most southern hunters. For us northerners, it's a very good windbreaking garment when utilized with layering. There is no substitute for playing the wind and staying as clean as possible.
I would rather stay clean and keep as much of my scent contained as possible, than use "cover scent" to mask human scent. A deer's olfactory senses are so acute they can pick apart 3 different scents... the fox pee, the racoon scent, and YOU... all at the same time. I would bet they can determine if a Doe passed on a trail 5 minutes ago or 2 hours ago.
I have noticed that on the farm, deer are accustomed to smelling humans at a distance and if the scent is faint they appear to act like no big deal, no danger. Sometimes and unfortunately for them, I was a mere 20 yards away when they thought I was 200 yards away. Scrubbing like a surgeon before going out and containing your scent as much as possible... works!
Ever had those heavy coveralls on when it was cold and when you unzipped the torso you could feel the heat escape into your face? Well, it's not only heat escaping, but human scent as well. Something to think about....