I HAVE liquid cooling, and still do not bother to overclock my i7 2600k CPU. I don't happen to feel the extra heat worth the marginal performance difference for me doing audio streaming.
Certainly the CPU-portion of things would run faster, but I am not taxing the CPU in any case, and most of the work is done by the hard drives, so I choose to just keep things quiet and will likely have a system that will last longer. Prior systems I have had that were overclocked just wore out faster, and I don't feel like dealing with that.
More power to those to do chose the overclock path, nonetheless.
Bob Bone