I might see this a little different....
Almost everyone I know buys products to fool a deer's nose OR at least does things to minimize scent. Any product out there offers SOME level of Technology- ANYTHING... Whether it's a spray that was designed by a chemist to eliminate scent, a scent covering product, Elimitrax, tooth pastes, gum, laundry detergent to remove scent, breeding & deer facilities designed to capture doe urine, Scent-Lok, anti-microbial clothing, etc, etc.
So, the differences: the LEVELS of technology- maybe there's a personal line you draw with how much you'll use.
COST: maybe you say, "hey, I'm cool with spending $20 on some scent spray but not $350 on a device".
SAFETY: Is that Carbon spray safe? Is this device safe? Is that anti-bacterial gum I put in my mouth safe? Is it ok to get spray on skin?
EFFECTIVENESS: I'm sure some of these work better than others, some might "HELP" a little, some a lot and some NONE.
I don't have the answer to any of these questions BUT I don't think it's unique to this one product. All are some level of technology, price, safety, success and all should be put through your filter of preference. Most everyone I know is trying to reduce, cover and destroy their scent, I also have some folks who don't do a darn thing and smoke in their treestand- to each his own. I sure don't find this product in a whole different paradigm than any of the others.