I've been using the Edsal Rivet Lock shelving for several years. When assembled correctly, and with their limitations kept in mind, they're strong and sturdy shelving units.

There are a few problems that I've found: The particle board shelves are so thin the tops sit below the shelf rails, leaving a rim around the entire shelf. If you have loose parts you don't want rolling off, this works fine. I prefer to slide things on and off a shelf rather than lifting them over an edge, so I raised the board surface above the rim by cutting and attaching fiberboard "rails" to the underside of each PB shelf to lift it above the rim. This worked but was time consuming and labor intensive. For my second attempt, I abandoned the fiberboard rails and let my printer do the hard work. I printed out some lifts that are easily attached to the perimeter of each shelf with hot glue. It takes a fair number - I use 14 for each 36x18 shelf and a few more for the 48x18 shelves. They work well and since they're hidden, high print quality is not needed.

Another problem I have with the shelving units is the sharp corners on the vertical rails. Not only are they hazardous, the edges makes the shelves harder to move - especially on carpet (moving this style of shelving is scary enough already.) Even on concrete, they tend to gouge little furrows when moved.

I tried a few end cap designs posted here, but found the sharp corners of the caps almost as troublesome as the bare rails. Also, most seemed a bit fragile when printed with PLA. I've posted the design of the cap I came up with. It's a little more heavy-duty than the others I tried. And when used as a top cap, it should help keep the ridiculously-sharp metal ends from drawing blood.

I've also tossed in a simple wedge I use to help with leveling the shelves. I use them in pairs to maintain a flat surface for the shelf legs. It's not fancy, obviously -- the design improvements available for an inclined plane are rather limited -- but they come in handy.