Product review (4 stars): very good
I do think these cases make a difference, even if it is subtle. First, I'm a bassoonist. Case is nice and big to give tons of room to breathe, stable and sturdy, and the pins are not solid but have channels so air can get in the tube. Reeds seem to be the same day after day. In the early process of making a reed, breaking it in, and letting it stabilize, I think these cases can prevent some of that. Often I open the case in the morning and all of my reeds start immediately crackling like newly formed blanks do. This suggests that they haven't aired out and adjusted or settled in overnight. However once reeds are completely stable and settled (wouldn't crackle as they dry out anymore), I have found this case to prevent warped corners and other strange humidity effects. At the same time, the case is about as expensive (or cheaper) than the basic fox plastic case so you might as well try it. Do be careful that you open the cases at least once a day to be safe - they will mold otherwise, even without the humidity packs in there - they seal air tight. Also, I'd like to be able to choose the humidity pack that comes with a new case, I use the 54%. I use this one because I found that it just keeps the reeds stable, without having them almost soaked. One more caveat with this though is that you will need to bring your water with you. I played an audition where I had put the wet/soaked reed in the case for the ~10 minutes walk around before you play. When I got on stage and pulled the reed out the case had done a wonderful job of drying it out!