Product review (5 stars): Does what it's supposed to
After studying in California where the weather is relatively constant, I moved to Germany where one's reeds are exposed to the humidity, temperature, and air pressure changes that come with the gamut of weather in a years' cycle. Most frustrating for me was having the heater dry out my house in winter so that each morning all of my reeds would be bone-dry and warped wide-open. I'd have to pinch the wires shut to be able to play on them, but after about 20 minutes of warm-up, I would have to pinch the wires open again and constantly adjust while I played. A reed that had great response and flexibility one day would break my heart the next. I also found that reeds which treated me great in Germany weren't nearly as playable in California. Tired of having my practicing marred by the inconsistency of my reeds from day to day, I bought this reed case. I assumed it was a gimmick, but seeing as it was so inexpensive I figured I'd give it a try. So far I am very happy with it. A reed left in the case overnight will have the same qualities the next morning.
  I am still somewhat apprehensive about leaving my reeds in any airtight environment, but I think the humidity packet must be doing its job of absorption because even after having played on all 5 reeds in the case before putting them away for the night, there does not seem to be excess moisture built up inside the case or on the reeds. Still, I make sure brush my teeth before I play and to clean my reeds out with pipe cleaners and dry them off after I play on them to avoid any sort of gnarly bacteria situation.
  Last weekend I traveled abroad for an audition. When I arrived, all 5 of the reeds in the case had the same tone and response that they did at my house in Germany. (Not that I brought any reeds in a different case in order to compare... I was a little more preoccupied with the audition than with the scientific process.) Unfortunately, the case did nothing for my double-tonguing or finger technique and I ended up totally screwing up the Beethoven 4 excerpt (crap!)