Drawback to my cart was noticed loading it first time.
While the wheels, 2 swivel 2 rigid look well spaced, the large diameter swivels shift the center of gravity and cart wants to tip. Design flaw? Overloading? A bit of each, plus variety of metal sizes. Real culprits, surprisingly, turned out to be the narrowest set, about 5' long, 4" wide, a 3" stack of 14 gauge.
Unlike yours, one area is over the wheels instead of inside and low, and frame of very lightweight materials.