Xav, given the exact same cooler size and the exact same amount of airflow (your own stipulations which I maintained), a blower cooler will perform worse than an axial-cooler.
Watch the video starting at
10m 06sec (I linked to it) to realize the mistake you made.
The process of heat transfer is convection, and it is greatly affected by the amount of difference in temperature between the heatsink and the air. Traditional blower heatsinks have long channels. The air heats up as it absorbs heat. As it heats up, it is able to absorb less heat. The longer the channel, the more the air heats up, and the less the air is able to absorb additional heat. Let's presume that the air in the blower -- at the same amount of airflow as an axial cooler of the exact same size -- reaches the same temperature as the heatsink 3/4 of the way down the channel. Thus, the last 1/4 of the heatsink does nothing since there is no longer a temperature difference between the heatsink and the air flowing by it. Thus, it is less efficient and the same size heatsink with the same amount of airflow provides less cooling.
Watch the video I linked to.
NVIDIA's latest FE cards use a well-designed blower/axial hybrid -- which I stated in this thread or in a different thread. But it is certainly not a traditional blower card. When comparing traditional blowers to traditional axial coolers, as I stated, what I said is true. Watch that portion of the video I specified, understand the mistake you made, then re-read everything I wrote. It all makes sense and takes into account everything you said (except for the parts where you were mistaken).