First off, case fans. Useful piece of equipment or just another excuse for computer manufacturers to part you from your hard earned cash? When installed in a proper air cooled system, with both an intake fan at the front and an exhaust fan to remove the excess heat then yes, they are an essential way to keep those components cool that don't have any form of heat protection, as well as lowering your otherall case temperature. Overclocking? With all the excess heat that is being produced a case fan is a necessity to keep your components safe and give them extra longevity.
Now, onto the product itself.
The coolermaster fan has speeds of around 2000rpm, and is described as being quiet. Now the definition of quiet is up for debate, can you hear it? Yes, but at the same time it's no louder than any of the other fans in the system, and it's rare to have a totally silent computer. Will it distract from immersion in games or watching movies? No, it's quiet enough to comfortably fade into the background.
This fan produces a nice blue glow, and situated at the front of my computer gives off a nice, tasteful blue light. Looks good during the day, and really gives your computer that little something else at night when it's dark. So what are the benefits of a fan with blue LED's? None technically, but it looks good.
Contrary to some opinions a case fan is so much more than just an excuse to spend money making your computer have shiny lights. It serves a useful purpose, especially if overclocking, and does add that extra something different to your computer in terms of the LED's. However the LED's might put some people off, it comes down to a matter of personal taste. If they're not your thing then go for a case fan without LED's, however I totally recommend this product