You know, Wizboy, I can attest to your claim. In a single setup, the VF700 outperforms the stock HSF greatly. However, I tested RTHDRIBL out last night in SLI w/ the VF700s attached and saw my cards hit 83C (I have two 7800GTs over clocked to 488/1150)!! I use an AN8 32X motherboard and the PCI-E ports are really close together. So close, in fact, I had to remove the back nipple brace on the bottom card because it was obstructing the fan on the top card.
You have to be right, airflow is everything for the VF700. Stock HSF is single-slot solution which provides more room between the cards, leading to lower temps in SLI.