I used two of the 7 ft 15 inch pieces to make a 4.5 ft round garden bed. I can't comment on how they weather since I just put it together, but I'm excited to see the rust patina.
These are incredibly heavy duty, well-made, and worth the cost. You have to be fairly handy to make the ring, but follow the directions on the video (you must use a ratchet strap), get a helper, and you should be fine. The result is worth it.
I highly recommend this product - it's unusual that a non-pro would have direct access to this level of quality product. It is expensive, but less costly than it would be to have a landscape company install it.