The fan runs very nice and quiet, even the sound of the blades is okay and can be reduced significantly by reducing the speed with still a decent airflow is generated. In addition, the fan is very well balanced, the vibration of the fan housing is extremely low and can be kept away by rubber holder complete the installation.
On several occasions I have read that the fans of the first generation after a relatively short time to be loud - now I hope that in the second generation (R2) is no longer the case and I am eager to see how the matter develops.