I've used the economy boxes for years with no issues. Most of my storage is put the files in and stack them in the storage area for several years with very little accessing of information so don't know how they would hold up for repeated or daily in and out use. However I have quite a few that are several years old and still doing just fine
Staples Economy Storage Boxes 10/Pack. These are great boxes. The handles are what makes this 10-times better than other cardboard boxes. So much easier to move these boxes because of the handles. Perfect size too not too big and not too small. Great for storing stuff and great for moving stuff. I use these as moving boxes then keep them for storage boxes. These stack nicely in a closet or attic.