I bought two. The first one I bought worked so well that I bought another. My dad caught wind of it and asked to borrow the second one for awhile. After having it for a couple days, he remarked how much better his breathing was at night -- we both have sleep apnea.
After being in the same room with the IB for awhile, my breathing does get easier, because my sinus problems start to go down. 🙂
If they are gimmicks, they must be magical, because I can tell the difference.