ipKonfig has just posted a review of the new Vantec CCK-6027D HSF. here's a snip:

"I'm sure most of us are very familiar with the CCK 6035D pure copper heatsink. While both have similarities, like the micro fin design, we again have the pure copper base. We are starting to see more heatsinks on the market with MicroFins, and they have one great factor, dissipating heat faster. The best aspect of the new 6027D version is that it's half the size of the 6035D version."