I grabbed this set for my closet shelves and the 12-liter size is perfect for socks and small bits, while the bigger one handles blankets without bowing. The lids actually snap down properly, which I didn't expect at this price.
The 40-liter box swallowed my entire winter blanket pile, and the 12-liter one is perfect for the kids' toy clutter in the living room. Sturdy enough that I've already stacked them in the garage without any bowing.
I was skeptical two boxes would cover my chaos, but the 40-liter one swallowed a mountain of kids' toys and still closed flush. The lids snap on snug enough to stack them in the garage without wobbling.