I upgraded to using the FOP 38. I works really good,It is the fasted fan that I have seen that size. I did find it very noisy at first but it seemed to quiet down after a couple of days. You also start to get use to it, I think. My board was showing the fans rpm at 6900 and then after a couple of days it was clocking at 7090.
You have to be real careful when clipping it on. The clip is way to tight. It might be a good idea to take a bit of tension off of the clip. I had to use a combination of a small pair of needle nose pliers and my fingers to get it on. Very TIGHT!!
If it does not come with grease you should definitly get some.