I have noticed some migratory covers have top cleats and others have a flat top with with just an end cleat attached to the side of the lid. I am curious as to the benefits of both. It would seem if one was stacking pallets it would be easier to do so with a flat top migratory cover? What is your grand wisdom on the subject? The following is a links to a migratory cover with a flat top and another with a top cleat.