I love them for moving and over the years have collected many - never had a problem with the movers not wanting to move them either. I mostly have the midsize Rubbermaid type - agree locking tops are preferred. We had no problem stacking them 3 or 4 high, after that, too far for me to reach. When empty you can put lots inside each other, tops on top so they don't take much room. Highly recommend - just collect them when they are on sale.