Antec Kühler H2O 620 and Corsair H60
The only direct review I could find between the H60 and the Antec 620, but its translated. Still valid info from looking at independent reviews I have found on other sites of the two coolers. About equal performance on the stock fans.
Silent it is not, however. 46dB idle and 68dB under full load. Every review I have seen on these two units suggest that they do not even match the cooling ability of the most commonly used air cooling solutions. Many of these air cooled units are even quieter than either of these "all in one" water cooling solutions.
If it were my dime, and I am fully aware it is not, I would either go with one of the air cooling solutions, or pony up the extra money for a better water cooling solution.