I have 3 of them in my Coolermaster 840 ATCS case - one as a bottom intake, one intake in the Scythe Kama bay and one for the Titan Fenrir. The three of them together at full speed are quieter than the single Titan Fenrir stock fan on it's own (but, admittedly, the Fenrir stock fan is rather loud). They are also quieter than the 120mm fans on my old Antec 900 at max speed.
I did get some vibration noise from the the two intakes, but these were fixxed by remounting the bottom fan and fitting a proper 120mm fan guard to the Scythe Kama bay.