I can see the fin design cross-section actually being effective over a square shape. As we know most of the air is blown through a fan is blown through near the outsides rather than the centre of the fan. This design seems embrace this, (although over elaborate) with its low centre pressure and low outside pressure near a heatpipes, the thermal transfer to the fins vs pressure vs airflow looks pretty good (still no idea about the fin spacing etc).
Only a test by SPCR can realy measure it benefits to us silence seekers - but having read X-Bit labs testing in 30-seconds it looks pretty good.
I disagree. Firstly, on the intake side the air will follow the path of least resistance, so it will avoid the 'blades' of the fins as much as possible. Second, air at the top and bottom center will pass less heatsink. Third, on the exaust side air will tend to flow in an expanding cone, avoiding much of the fins area in the middle of the sink.