I love sweetening my smoothies with fruit alone, but that usually means using a banana. While I love bananas in smoothies, my husband, his sister, my niece, and lots of people I know really don't like everything to taste like a banana.
This smoothie has honey, which is a good, natural source of sugar, but you probably should accompany this smoothie with whole grains so the fiber can help you digest the sugar. (Fruit has natural sugar in it, but it also has fiber which helps you digest the sugar in it. Honey doesn't have fiber in it.) The strawberries I used were very sweet, which helped make a tasty smoothie.