The first time I made this smoothie, I made it exactly like the recipe (with 1 tablespoon of protein powder added). My youngest son finished his cup and said, "More please."
Since then, we have mainly used blueberries in place of the peaches. They like it better with blueberries or strawberries and blueberries combined. I've also started adding ground flax seed. Especially with the dark blueberry color, the kids don't notice it. I have been using freshly squeezed orange juice, but I'm not sure it matters in terms of the taste.
We've probably made some variation of this recipe about 6 times now. It helped me use the remainder of a half gallon of buttermilk from another recipe that would have otherwise been thrown out. Thanks for the recipe.