Firstly, let me state that since I have already written a review of the first revision of this product most aspects are the same and that this review is mainly about the differences between the two versions. For further information on this product, therefore, please see my review of the earlier version.
They both use a thermistor temperature sensor to control the fan, use a block of copper on the base of the heatsink, have a unique fan shape and offer low price, low noise and great cooling. Installation is easy on both models thanks to the wide clamps that fix at six locations to the socket. Pre-applied thermal transfer material means no messing about with thermal paste.
Now, what are the improvements of the revision 2?
(1) The shape of the fan mount has been changed to allow even less disturbance to the airflow. In other words, the arms holding the fan motor are even further away from the fan itself thereby lowering noise from turbulent air.
(2) There are now rubber mounts to clip the fan assembly on to the heatsink. This is to reduce noise from vibration.
Indeed in my other review I pointed out that I could hear a slight rattle from my old one, I think this is what they have tried to remove on the newer version. Well, it worked. This newer version is a little bit quieter thanks to the improvements. Given that they pretty much cost the same you should probably always get the version 2 if you can. But, if you can't get the version 2 rest assured that the difference in noise level is un-noticeable unless you put your ear to the PC case. In terms of cooling functionality I have seen that they are the same as this one ended up going into another Socket A system with exactly the same processor inside. I got the same ultra-stable system performance and very similar operating temperatures.