Summary: This fan pushes an absurd amount of air, and is actually quite focused even though it is not mentioned in the description. You can feel the its pushing even at lower speeds. Works wonders cooling hard-drive cages, that's the primary function for mine. However it would make a great radiator fan or heat-sink fan as well. It can get loud at the full speed, but not in an annoying way, it will just hum quite loudly.
Summary: I ordered six of these to replace all of the 3-pin fans that my computer's case came with. I use Corsair LINK for controlling my fans, and their modules could not properly control the 3 pin fans. These fans fit perfectly, as I expected, and were much quieter than I anticipated. Now my computer is whisper quiet at idle, and has a steady climb in noise as the load increases.
Summary: I got two of these fans for my build. One to replace the rear stock case fan in my Cooler Master Scout 2 Advanced case and one to replace the stock fan in the Cooler Master Hyper 212 EVO CPU cooler. These are four pin fans for ultimate control and with better bearings than most. They are quiet and move a lot of air. I've seen other reviewers say they are noisy, but that is only when they are running full speed. Mine rarely get over 60% and are not heard at all at 50%.
Summary: These fans rock, pwn, tons of CFM, easy to clean and high quality! These fans come with everything you need to hook up the fan, and again the quality is top shelf! Favorite fan hands down ATM.
Summary: Got these very quickly, and I can honestly say I am impressed. They have aluminum bodies, so they can contort a bit and they are very lightweight. The power of these fans is impressive. I am using 2 of them in a push/pull configuration on my liquid cooler, and it keeps my 8-core Bulldozer a chilly 30 degrees even under gruling bechmarking. Would work great for a case fan or other cooling solutions. Will be purchasing more of these bad boys as my older fans start to die.
Summary: This is a great fan, particularly if you want a coll yet silent system. However, if you are a power user and serious overclocker look elsewhere. I recommend the scythe fans. I bought four of these and was perfectly happy with them until about 6 months out of using them. The blades started to break off and obviously made the fans unusable. I believe this is only because I ran the fans at 100% 24/7 due to high cooling demands.
Summary: I recently purchased two of these for my Corsair H100 radiator, and I have to say, I seriously doubt the rated CFM of this fan. I noticed that not much air was being pushed through the radiator grille and was surprised to find that much of it was leaking and spilling around it. Not only that, but these fans are extremely loud in a horizontal plane. They made my computer sound like a jet engine, they increased the noise of my computer by about 10dB.