Confusion about Zalman NC3000 Series notebook cooler

I had a couple of questions about the Zalman NC3000 cooler.

1) I've never actually seen specs about the CFM which this model with a 220mm fan is capable of, however one retailer with a review on youtube postulated that it would probably be around 80-90 CFM at the 620-720RPM (plus/minus 10%) speeds it reaches.

I'm confused how the Antec 200 notebook cooler with a smaller fan has a lower RPM (400-600 although it's with plus/minus 150rpm!) and has 87.9 - 115.7CFM? From the design is seems that the zalman has a better design due to aluminium surface and a lot more ventilation holes covering a far greater % of the surface area. On a side note, it's also about 40% cheaper here in the UK compared to the Antec cooler.


2) Zalman said the following on their site about replacing the fan in their FAQs:

This implies it can be done. Curious if anyone has tried seeing how easy this is and if you can just use a standard 3pin connector? Also, does anyone know what the thickness of the stock fan is? I can't seem to find any dimensions for the 220mm fan in the cooler.

On a side note, I've been looking around for 220mm fans but there doesn't seem to be much choice around, especially given the current noise rating of the nc3000u/s at 17-23dBA (give or take 10%) and being reluctant to go up from that reasonable figure.

The only upgrade I can across with that has similar noise and greater airflow is:
Akasa AK-F2230SM-CB 220mm Silent Case Fan - 4 Pin

However this has a 4pin connector. It does however provide 95.63 CFM at 600rpm with 23db.

Cheers