I’ve been using them very happily for the last two grows/cures. I put them in at around 60-62% (right off the dry rack in the 58-62% bags) - no burping, nice cure, and yes stay very effectively in that range. Really like them. Less storage space and less effort/worry than jars. First times I started in jars dimly simply to gauge humidity levels, but that was unnecessary. I’ve also put hygrometers in the bags a couple times, and that has simply proven that they work well. I reused them a few times now also.