Extreme Overclocking have posted a comparison of five different heat sinks, which oddly enough each came stock with a different style fan. Heres a Quote:

    This roundup is five of the latest heat sinks out on the market. Three are all copper, one is all aluminum, and one is a hybrid mix. Also each heat sink came with a different speed fan that varied from the whisper quiet to the screaming loud! However in addition to their stock fan on all heat sinks, except for the Antec, I used the ever-popular 38CFM Delta so a more accurate measure of performance could be given.