Both, for better cooling and the sycthe's make a hell of a lot less noise than the stock fans. I was going to replace it with the OCUK stock range of coolers last month when it was £46 as it had a thicker radiator but after looking at some user's temps I decided to keep my H60 as there was no difference in temps.
Thanks for the response majnu, I take it you've not had any issues with the noise of the pump?