I really wish more manufacturers would design their heat sinks like this. Blowing air over fins is very inefficient. Turbulent air has circulation as it enters the fins and kills heat transfer. Pulling air through fins that are long enough (to give time for the flow to adjust using the Darcy equation and such) allows for full flow and boundary layer adjustment.
Sorry to slap on all of the theory here, but it's the complicated engineering behind something that looks simple (it can be pure hell). I really appreciate these efforts, and you should too since you can over clock higher or play cooler