I have three of them built into a Phanteks Enthoo Pro (two front, one rear) and can run at 350 RPM. Here so much air is moved so that the hardware is sufficiently cooled (and that is very warm with a GTX 480!). The fans can not be heard with my configuration, but this of course will be loud at 1200 RPM.
The processing of the fans is good, I have nothing to complain about. They are also definitely an investment that will also fulfill their duty in years, and the faint!