I second this. I have an i5-4690k OC to 4.4, any higher gets unstable. While working on the OC I had it up to 4.6 and during stress test, before crash due to instability, my temps went to around 70, but thats during stress test. Now that I have it at 4.4 during normal use it's 55-60.
My point with this is why do I need something that cools any better than that? Air gets the job done, well, and I don;t have to ever worry about water in my system, pumps going out, radiator leaks....nothing. Put it on, it works, no additional maintenance, ever, and it works well. That's why I never recommend water coolers anyway.