I've used them since their advent and I've had great success with them. They are not a panacea, but are a tool to aid your scent control efforts.

I've killed animals that were directly downwind of my stands. As I've said before, scent control is sort of like playing a radio in the woods. You simply cannot turn it off, but you most certainly can turn it waaaay down.

Are they "worth the price?" No, not if you buy the name-brands that are out there. I used the military surplus stuff because no matter what brand name outfit you buy, wear and tear and washing it will cause it to lose its utility value. The name brands effectively last no more than 3 years in my opinion and I feel that 3 years does not justify the cost, but, the military versions are available at a fraction of the cost, thus justifying the expense in my book.