Summary: I got one of these to replace a noisy fan in a case with two fans. Even though the other one wasn't defective, I decided to order another one of these and replace that one too. The fan comes with rubber pieces to mount it. I know from experience with other Antec fans that that works well, but I didn't feel like taking out the motherboard to get the clearance I would have needed to do so.
Summary: I bought this to replace the original fan in my Antec Sonata case. Figured it should be an easy install since it is also an Antec fan - wrong!. The rubber mounting "pins" are a real bear to pull through the fan mounting holes in the case.In fact, I broke one by pulling too hard on it. Luckily, there were 5 in the package. I ended up putting silicon O-Ring grease on them and it was still quite difficult and would highly recommend this.
Summary: Super quite although not amazingly effective. You certainly will have trouble hearing this fan. Also! Make sure you buy fan screws or have some that come with your case as this package comes "screw-less" including this silicon mounting "screws". They're nice, but don't fit all cases or work in all situations.
Summary: They're definitely quiet. Don't move a lot of air, but those are kind of directly related. I installed 2 in my HTPC case since the CPU fan kept revving up while I was watching shows. Now that fan doesn't ever come on so my computer is nice and quiet. I'm happy with them.
Summary: Pros: It really is silent. Cons: It is hard to fit in a case... if it were not for this, then I would have given this fan 5 stars. So, I got this to go in my Cooler Master N200 case. I was wanting to put it in the back of the case to push air out, while moving the fan that was there to the front to have dual fans pulling air into the case from the front.
Summary: This fan was was to install, I have never used the rubber "tool-less mounting" systems before, and It worked just fine. I have this fan mounted on the GPU side of my Antec GX700 case, a product I am also quite pleased with.
Summary: Barely noticeable sound unless you put your face up to it and pushes a decent amount (35 CF/M) of air. The only problem is that you may have to use case fan or mounting screws, because the rubber ones didn't want to work for me.