I thought this recipe used too much sugar for my kids. I also wanted a much more tangy filling so I changed the recipe as follows: Used 1/4 cup sugar in crust.
Doubled filling using:
2/3 cup granulated sugar
5 teaspoons freshly grated lemon zest
1 cup lemon juice
3 large egg
1 large egg yolk
3 tablespoon white whole-wheat flour
Turned out wonderfully tangy and the kids loved it!