we've heard of the MC-370 before, but it seems that it's grown up a little. Go check out Mikhailtech for their views of the new Swiftech MCX-370 HSF. here's a snip:
"The main idea behind the use of these rubber spacers is twofold. First off, they reduce noise, about 1-2 decibels according to Swiftech. This is achieved because the fan is no longer in direct contact with the heatsink, and the rubber absorbs a great deal of the produced vibration. Secondly, they actually improve airflow. In the older MC-370 there was a "dead zone" right below the fan, as the motor sat on the pins and no air could get in there. Also, fans tend to heat up a bit, so having a warm motor on a heatsink is not such a "hot" idea. Having the fan a bit above the 'sink allows for air from the fins to creep under the dead zone and cool those previously "inactive" pins.