Thick and creamy - more of a strawberry-banana smoothie than a strawberry-kiwi smoothie - would increase the kiwi next time. I'd also use one less banana and more soy milk, for more pronounced vanilla flavor.
My son and I really enjoyed this smoothie. No, you can't taste the kiwifruit, but you still get the added health benefits from inlcuding it. I am sure that we will make this often.