There's very little difference between small & large nestabilty sets, they are designed so that they step in between each other. ie the largest of the small set is inbetween the largest the the 2nd largest of the large set. I've got the small rectangles and wasnt going to bother with the large ones because there is so little difference but I've just done a couple of pyramage cards with them and would like there to be less of a size difference between the layers.