I was impressed with how Martin's results with the Skythe SlipStream fan, so I got one to try it out myself. Against my MCR320, the Slipstream was painfully inferior to the ZM-F3. When the noise of each fan was matched, the ZM-F3 moved a lot more air through the rad than the Slip did... The Slips have a ticking that is very annoying and very audible, especially in silent systems. On full power, the Slips most definitely move more air than the Yate Loons (medium) or the ZM-F3, but are always (much) louder. I returned the fan to the store, and bought two ZM-F3s instead.