If the CLC solution was developed for these with their insane pressure and airflow, I'm not surprised it can't be cooled silently.
Blower style fans are superior to axial fans when it comes to pressure and airflow. I feel Corsair just cheaped out on the fan when it could have been much better quality, as mentioned the blower fans used for reference card like the 980 ti have to handle much higher heat loads and still manage to be "quiet" the intel hts1155lp and the blower fan I'm using, a Delta KDB are a good example.
I've tested my i7-4785T (35W TDP) and 4790K(88W TDP) with it and the results for temperatures were:
4785T Prime95v28 Max Heat 51.25C
4785T Prime95v28 Max Power 50C
4785T Realbench 30 minutes 45.75C
Please note the HTS1155lp is rated for 65W TDP max and Prime95 is also a worst case scenario.
4790K Prime95v28 Max Heat 95.5C
4790K Prime95v28 Max Power 92.5C
4790K Realbench 30 minutes 88.75C
With the 4790K Prime95v28 Max Power you can definitely hear the fan but for what it is it is silently. Better then any laptop fan by a long shot and it is even running a high wattage chip.
PS: Tests were done on a Gigabyte H81T I tried running the same test on my ASUS Q87T which has a super dumb CPU temperature threshold that sets fan speed to 100%, it isn't silent anymore at 4000 RPM :S.