I have an SD rack on my D1, and it has some good points like quality of build, looks, and function. The downsides are increased wind noise, at least 1.? mpg reduction in gas mileage, and weight (heavy).
From what I can tell of the Hannibal, it beats the SD on weight (lighter aluminum construction), impact on gas mileage (more streamlined design), and function (large flat surface).
Now if $$ were no object what rack would I go with???
The SD in a heartbeat. Because it fits the disco like it was part of it. It enhances both the looks and functionality of the truck. The Hannibal, on the other hand, looks like a roof rack.