Summary: Super quiet, no noticeable rise in temps in my air-cooled case. This fan comes with two adapters to limit the fan speed and further reduce the noise. I'm not using them at the moment, but I thought it was a nice addition.
Summary: I ordered 3 NF-R8 PWM 4 pin fans (one for exhaust and two for intake) to replace the existing Cooler Master 80mm PWM fans as those were slightly too noisy for my environment. The reduction in noise level is significant with the NF-R8 PWM fans! I cannot believe how much quieter these NF-R8's are while the air flow appears to be similar to what it was before based on the system temperature monitor.
Summary: You can tell straight away that this is going to be a quality piece. The packaging is very nice retail quality. The interior rubber fan mounts are rugged and stood up to my ham-fisted installation techniques! The fan itself spins freely and is very smooth with no perceptible mechanical feel. The included power adapters looked to be of good quality but I didn't use them in my install. The fan runs silently in my install and moves an impressive amount of air.