This was the only one we kept past the start of corn planting, and it was on grass only half a mile from my house.  Mice got under the first few feet of it and let some water in.  Pulled the first grain cart load off and dropped in a small bin to put air on the corn for a couple days, then blended it back.  The rest of the bag was amazingly good quality, looked like the day it came out of the combine.  The drawbacks are, if you fill 15 bags you will work every day for weeks on end in some terrible weather to get them hauled in the winter.  Much better than trying to run a combine in the winter though!