The difference between the top and bottom pie crust recipes is in the proportions of butter to shortening. The bottom uses less butter so it doesn't taste quite as good, but it will be flakier. The top is supposed to taste a little bit better (I didn't notice a difference honestly), but will be less flakey and can therefore be better for making small details in your pie. You can use either for either the top or bottom, this is just how I did it and I was very happy with it! Whichever one you are using, its still important to keep the dough cold, or the fat and water react and it won't turn out as well after you finish baking it.