Here are the specs for the Antec PRO 120mm DBB Case Fan:
Ball bearing design
Volumetric airflow: 79 CFM
Fan speed: 2,000 rpm
Acoustic noise 29.8 dBA
Basically, this fan moves more air (CFM) than stock CPU case fans and at a higher speed (normally 1,000 rpm is average) but the noise is nearly twice as high (normal case fans are around 16-19db). So you'll get noticeable cooling performance but at the cost of noisier operation.