I was recently asked by a close friend why I thought the brand name on the case fans I use was so important. The short answer is the brand name is not important but the quality of the fans I use is. It just so happens that Noctua and quality go hand in hand as they continue to be a leader in PC cooling technology. Their newest offering is an update to the award-winning NF-A14, called the NF-A14 PWM which incorporates, you guessed it, high-speed PWM.
The new NF-A14 PWM is a move towards higher performance without sacrificing the quiet operation Noctua is known for. It now operate at a maximum speed of 1500 RPM (up from 1200 RPM) for higher air pressure. These are the perfect fans for your case, CPU heatsink, or water-cooling radiator thanks to their combination of high airflow, static pressure, and PWM design. Basically anything the fan needs to "blow through" is where this fan will do well. For example, the increasingly larger sized water cooling radiators that many enthusiasts like using will benefit from this upgrade.
I could talk about technology, research, and show off a bunch of diagrams to explain my standpoint on quality fans, but there is no substitute for experience. Go out and get a set of the Noctua NF-A14 PWN fans for your PC now. Once you hold them in your hands, you will understand the difference a high quality air cooling product backed by a 6 year warranty makes. Even if the colour clashes, there's no mistaking that you're using Noctua fans.
More information is posted at the link below although pricing and availability were not available at the time of this posting.