Well, I'm considering building a different set like Rogue's design. Anyone interested in these? They're hardly used (and have been used really only to store things on top of since I've been injured).
They are these only slightly modified: Jerk Blocks
I changed the top retention setup to ripped strips of plywood vs. quarter round molding (and have included it on one side so it won't be slipping off a side). I used standard wood screws for the internal supports and these fasteners at the corners of the boxes:
40" L x 20" W x 40" H