The Super Cube is a nice radiator. The copper tubing and fins are ideal at delivering heat to the outside air. It's also sized nicely to fit inside a case.
That being said, the heater core type on the left shows the waterpath through the radiator. Because the water is broken up into so many different tubes, and the large volume of space in those tubes, the water slows, and has more time to cool off. Also it has alot more surface area of water exposed to the matal, where the heat is removed.
The one on the right illustrates (very simplified) the waterpath through the cube styles. It does not slow down, as the tube diameter is nearly the same as your pump tubing. It also has limited contact area with the metal. The length of the tube tries to make up for the these, thus it winds back and forth for several passes.
Now, both of these types of radiators do a good job for computers. The heatercore style has more than 10 times the heat capacity that a normal chip produces, but the cube style is no slouch. It will keep up with most processors, and even peltiers, it's just not "the best". The heater core also requires adaptation, like shrouds for fans, and a mounting system, all of which are built into the cube.
Heatercores are often cheaper too.
Hope these help ya out.