Hold on there...You're going to have to consider the fact that even though the noise level is lower, the static pressure is lower as well.
For example, if you have 2 fans, say an 80mm and a 92mm, and they both have the same airflow rating (75CFM for example), then the 80mm will perform better because it will push the air harder than the 92mm.
The Vantec 92mm Tornado runs 119 CFM at 56dBA. That is loud...I know because I have one. I would have to say if you want a balance between noise and performance, the Thermaltake Smart Fan 2 is a good way to do it with
[email protected] I am considering changing to that myself if I can't get my temps any lower. I am starting my shroud project today, so I'm going to see how that goes before switching.