Hardware Canucks tried the Noctua NH-D15 CPU Cooler
A quote from the article:
With the advent of easily installed, quiet and high performance all in one water coolers like Corsair's Hydro series, the lay of the land has changed for air-based CPU heatsinks. Many don't find them as versatile or able to deliver same same excellent results but technology on the heatsink front hasn't stood still and Noctua's new NH-D15 is meant to effectively close the gap between air and water.Noctua NH-D15 CPU Cooler Review @ Hardware Canucks
The market where the D15 finds itself in is a cluttered one with literally dozens of options regardless of what your preferences are. Where Noctua has always distinguished themselves as designing some of the quietest coolers around and that's something unique when it comes to higher performance solutions. In an effort to deliver water-like results, it's often a race to the bottom of the acoustics pile but that may change with the NH-D15