The only down side is that the are fairly large, so if you fill them up small items tend to tip in on each other. They are also hard to keep open when you first start filling them (or maybe I am just uncoordinated.). Of course, you know I am always looking for the cheapest ways to solve a problem, so I had been mulling solutions around in my head. Then, the other day I had an ahh hah moment! I was taking some empty cardboard boxes out to the recycle bin, when I realized that several of the boxes were just the right size to put in the bottom of my reusable bags.
I'm so happy! I reused a few pieces of potential garbage, now the bags sit flat while you fill them up, and the reinforced bottom is much more stable when it's full of groceries (or produce from Bountiful Baskets). I just tuck the pieces of cardboard against the side of the bags and fold the bags up when I'm not using them.