which is the better case fan?

Solution
The Corsair AF series are better, but much more expensive. Also, make sure you have at least 2-3 inches of clearance eg. no HDD cage, cables, etc. behind the fan or else it is going to drastically reduce the fans performance.

Nuclear101

Honorable
The Corsair AF series are better, but much more expensive. Also, make sure you have at least 2-3 inches of clearance eg. no HDD cage, cables, etc. behind the fan or else it is going to drastically reduce the fans performance.
 
Solution