My previous (admittedly not that helpful and perhaps unfairly judged) review here was not too colorful, thanks to the noise the fan may or may not have made. 7 downvoters have spoken, so I decided to give it another go.
In hind-sight, the annoying, low hum may well have been case rattle. What I can say, is that one of these fans that I used as the rear fan in my old gaming PC for ages was really good. Great pressure, great fitting, and the noise was acceptable. With a fan controller, these are brilliant. Not sure what to make of the noise I experienced with the other Corsair fan; perhaps it was just a dude, who knows. Not sure what else to say about them, ... they're fans!