Yes I used one for about 3 months last year and it did not seem to help me much either. I then did not want to pack and bring to Florida for the Winter so I turned it in. My Dr. now does want me to try it again, to which I agreed to. Mostly because she put me on another mucus thinning medication (along with albuterol & 7% saline). Now having trouble with insurance coverage for the vest.