Freezing peaches without sugar is a healthier option that also saves you a step. Freezing peaches with sugar can result in a flavor that is more sugar and less peach. This is because the sugar will draw out the juices from the peaches, making them sweeter. However, this can also make the peaches less flavorful, as the sugar can mask the natural peach flavor. Additionally, if you are using the peaches in a recipe that calls for a specific amount of sugar, the added sugar from the frozen peaches could throw off the balance of the recipe.