I have this. Pretty happy, though I have had problems with it which I believe is due to my too small power supply (350W). It works only if I reset the computer after the hard drives spin up. Kind of annoying. If I don't do this, it will lock the computer when I try to launch some 3D app. It is 100% stable after doing this.
The one pictured has a single speed fan, but it is VERY quiet. There is no way to adjust the speed of the fan unless you add a potentiometer inline with the plug or something. Even if you do that, there is no RPM sensor on the fan, so you wouldn't know how fast the fan is going without physically looking at it.
One other thing, be sure to check the heatpipe before installing, it is not very well designed and bends easily. Mine was bent into the fan. A bit of pressure bent it back to the proper place.