well i've gotta say these appear to be fine fans indeed
just compairing with the sharkoon 1000 atm (using the blue 5.25" zalman fan controller btw), the airflow seems greater by far, it's not even close. i got both fans and put one next to each ear, you can clearly hear the Noc is louder upto about 3 inches away (airflow noise not motor), but any further away than that and i cant hear it above my system noise.
the full speed sharkoon pushes more air than the Noc on lowest speed (to be expected), but there is not much difference. the Noc is far superior if both are on full, but as i said you can hear the air flowing if you have your head next to it.
colour aside, these are damn good IMHO
also tested today...
Akasa blower / exhaust fan
hmm
too noisy. always that strange motor noise with blower fans :/ . but i really need something to get rid of the heat from my gfx card. however this is not going in my system.
Akasa AK-1704RDS Crystal 80mm 4x Red LED Fan
to replace the stock fan in my Lian Li EX-23B HDD Bay which is currently keeping my Raptor quiet
, attached to fan controller switch (off 5v and 12v), which worked out better than i expected. 5v is silent and the LED's dont come on. and 12v which is pretty quiet and the LED's come on, and subtley shines through the front grill of the bay.