I've made this recipe many times and it's always a hit. I first tried sholeh zard years ago at an international fair and became obsessed with it, so once I found this recipe, it became a firm favorite. Using water and butter rather than milk makes it simultaneously creamy yet light; the slivered almonds give it a great texture; and the flavor combination of cinnamon and rose water is just fantastic. I could seriously eat this all day long. It's also really easy to make - aside from needing to give it the occasional stir, it pretty much monitors itself, so as long as you don't have the heat up too high, you shouldn't have problems with it sticking as the rice dissolves. Incidentally, I've also seen sholeh zard decorated with fresh pomegranate seeds, along with the cinnamon, pistachios and almonds.
I used 1 cup sugar for 1 cup rice though not with this exact recipe and it was sweet enough for us.