Smoothie King is good for what it is... a smo cone (mix between a smoothie and a snow cone).
I personally enjoy Jamba Juice more because the flavors taste more fresh and flavorful and the drink itself is blended to the point of being a real smoothie. Smoothie King is always pretty lumpy and icy. It's still good, but I'd take Jamba Juice any day over Smoothie King. And I feel like Smoothie King is more expensive than Jamba Juice.