I have one and its OK . I looked at all of the sizes in stock at Tractor Supply, and noted that my little 48" model is built with the same side plate and moldboard thickness steel as they build the bigger ones. I feel it is heavy enough for the size. There may be a size where this gauge material is inadequate.
I have slightly bent the flat steel arms where the two main 3-pt pins bolt through. This was done on a 20 Hp J.D. 4100 tractor (2500 pounds with loader on), while extracting up-to-4" tree roots. They will be easy to straighten, and once I have done that I will add a cross piece to beef it up. No big deal.