I'm glad you all posted, I have the 580 lb Four Drawer Roller Cart and love it. The only problem I have with it, the drawers lock when the lid is closed and I often use the lid as a worktable and find myself tilting the lid open to access a drawer and having parts fall off the lid. Pisses me off but it is my fault, I have a work table opposite the tool box wall that I should be working on. The casters are heavy and the steel is thick, I give it two thumbs up easily. Also, I got mine for $100 from HF, it was the display model. They had sold out during a tent sale and I asked the manager to sell me the display model, it was already set up too!
I guess when I get another box, I may look into the HF large boxes. Here is my cart, excuse the mess.