We have used crystal single serving milk containers at the school where I work for many years. There has been one consistent issue: the containers leak. Without fail, there is milk running all over the floor of my cooler units. We have to clean up the puddles almost daily after a delivery. They switched cartons for a while during the shortage, and leaks were not an issue. Since they resumed doing whatever it is they are doing now, it's a constant mess. If I had a different supplier I could go to, I would.