Good quality, and the constant airflow was extremely quiet ...
598964
Good quality, and the constant airflow was extremely quiet although a low hum was noticeable.  Definitely requires the mattress topper.  Sheets fitting properly can be a bit tricky as getting the corners to fully cover and secure can be difficult since there isn't really a natural pocket for it to grab as it sits so tall and is basically a single mattress but thicker.
2296692
quiet, well made for a $100 fan,  I installed a competitors in one of the other rooms, and there is a huge difference in quality.  I restore houses, so I'm always adding 4-5 fans to every house.
2849476
Pushes a ton of air and produces very little noise. I bought this to pair with the 200mm intake fan that my H630 case came with. With the two of these, my case has phenomenal air flow, and good positive air pressure.
4098822
This fan moves quite a bit of air.  At full speed, it makes a decent amount of noise while moving quite a bit of air.  At lower speeds, the fan blades are near silent, but there is a hum that comes from either the motor or the bearings.  That hum made this unusable for my purposes in a HTPC that recently was moved into living space and needed to be as silent as possible.  The fan itself is very well built and in a fairly slim frame that will fit in tight locations.  If it weren't for the hum, this was the perfect fan for my use due to the amount of air it moved and how quiet the fan blades were.  I had this hooked to a PWM port on my MB and depending on what speed it was at, you could clearly hear it across the room.  Even using the resistors that came with it, the slowest setting had the hum.  Like other reviewers I thought the hum may have been due to using it in a horizontal mount on the top of the case.  So I moved it to a vertical mount as the rear exhaust fan and the light hum is still there.

I have since purchased other fans to replace this one:

Corsair Air Series SP120 PWM Quiet Edition
 - Near silent at full speed (full speed is way less than this JetFlo)
 - does not move near the same amount of air as the JetFlo even with the JetFlo running near the same RPM

ARCTIC F12 PWM
 - Pretty quiet at full speed (full speed is less than this JetFlo...closer to the low speed of the JetFlo)
 - Moves almost as much air as the JetFlo at equal RPM, yet much quieter
 - Not nearly fancy of a mount or quite as slim as the JetFlo
 - very nice harness setup to allow for chaining PWM fans off of a single MB header (includes separate tach plug)
3173721
This was a relatively inexpensive fan so I wasn't expecting a lot from it.  However, I can't say they could do any better.  the quality feels good, it's silent running, and I'm very impressed with the volume of air that it moves.  I'd definitely buy again. I ordered this for my son's computer when his fan quit and we needed one right away.  It had only a single fan mount.  Once we got his computer running again with this new fan, he shopped for a new case and found one.  He liked this fan so much he pulled it out of the old case and added it to the new case.  Good stuff.
3063458
I am very satisfied with the quality of these Silverstone Tek 120mm Fine Fan Filters, since the installation of the fan filters (which was stupidly easy) the amount of dust in my system has dramatically decreased. I have to clean the inside of my desktop significantly less.

The only downside I can see is the fan filters are restrictive on airflow, which is expected.
648148
Upon opening the box I was instantly impressed. The quality of the fan with solid metal frame coupled with the detachable speed control cable, which is good incase the cable needs to be replaced but I doubt it will. Its very quiet and the speed control is sensitive enough to get the exact amount of airflow you need up to 60cfm, it might be possible to speed it up but I don't recommend it.
4884905
This 80mm double ball bearing fan was well worth the price as a rear exhaust fan in my new custom pc. It is whisper quiet and has decent airflow. With the fan volume virtually nil, while the airflow is decent for the price range, to get better air movement you will have to sacrifice a low volume or look for a more expensive fan.

For the price, this DBB fan has exceeded expectations.
1912038
I bought these to hopefully make my computer next to silent, but this didn't really help.. at all. The quality of the fans are excellent, but the noise is none less than that of the included case fans from Antec!
1203800
Very quiet fan...barely notice it's there.  It's been running non-stop for a couple of months, no issues.  Perfect amount of airflow for sitting behind a desk, and quiet, so it won't bother others in the office.

Definitely recommend this fan for a single user, desk/office situation
3681524
I've purchased a number of high end CPU coolers over the years, but this is my first one from Noctua.  The packaging and documentation are excellent.  Installation was easy.  Most important (to me) is that this thing is silent.  The package comes with everything needed to install it, including thermal compound and a screw driver.  It also includes a "fan silencer" that reduces voltage to the fan to lower the RPM and therefore noise.  It is easy to mount the heat sink and fan in a number of different orientations to give yourself the best air flow through your case. I tried it with and without the fan silencer, and decided not to use the silencer since the fan is still very quiet without it.

My CPU is a lower power one (45W thermal design power), because noise is more important to me than performance.  The Noctua cooling fan stays running at a very low RPM and is silent with my CPU temperature sitting at about 29 degrees Celsius. Much better than the annoying high pitch whine from the stock fan that came with my CPU.
3738874
I bought this and a mega-quiet Broan XB50 fan for my bathroom.  The old fan was a little piece of junk and was insanely noisy, and since it was wired to come on with the bathroom light, it wasn't possible to take a quiet, relaxing, contemplative dump.  This was really harshing my mellow.  Also, there was no backdraft damper so the bathroom would be 15-20 degrees colder than the other rooms in the house.  Not a fun bathroom to use.

Install was easy.  There is a cotter pins that protrude from either side and holds the piano hinge in place, but I just taped right over them:  they can remain fixed in position and the flaps still work as intended.  I don't know why so many people were griping about this, it was not a big deal.

As for the backdraft prevention, the dampers seal against a foam ring.  A very slight amount of cool air still comes through, but it's 95% mitigated and I'm satisfied with this.

As for the noise - the little semicircular flaps produce a fluttering noise, which is a real bummer because I spent top dollar on a quiet fan.  But it's a lot more quiet than the old fan, and keeping the cold air out is more important than total silence.  If I were to do it over again, I would try to find a backdraft damper that didn't produce as much noise - there is a sleeve damper I've seen that looks interesting.
1360999
Absolutely the most quiet fan I've ever encountered! Very solid air mover. Been running this almost non-stop next to my humidifier for a month now and no issues at all.
2121627
I installed this fan in one of my client's workstations as an exhaust fan, and I couldn't believe how quiet it was. Even when I put my ear close to it, the sound was still negligible. I always make sure my clients' workstations stay quiet, and so I'm very meticulous about the parts that I pick for the custom workstations, especially case fans. I've used Scythe case for many years, because they have so many different selections of case fans for different needs, but then suddenly they don't sell them in US stores anymore. Since then, I chose Noctua fans for all my custom workstations. The Noctua fans were very quiet fans also. When I came across the Scythe fans on Amazon, I was surprise they have the 120mm 500 RPM fans. This new version of the 120mm 500 RPM fans is even more quieter than the ones I used a few years ago.

This case fan is not recommended for cooling systems that generate a lot of heat due to its slow RPM. To me, this fan makes an excellent exhaust fan, but not a good intake fan (unless you can put two of these fans in the front), since its ability to move air into the case is not comparable to the other higher RPM case fan. However, if you want your system to stay quiet, but also want the system to stay cool, you can definitely try Scythe's other case fan selections. Although the others have a higher RPM, they are still very quiet compare to the case fans from other brands.
2712766
I had purchased this for a small wall-mounted rack in a closet, and thought with just a few 120MM fans that this would be fairly quiet. It was not. I debated switching out the fans for quieter ones, but then decided one or more strategically placed laptop fans might give me the cooling I needed at a fraction of the price. I guess if you had an enclosed rack and noise was not an issue this could work well. It definitely provided good air flow, and seems solidly built.

The only other gripe I have is that it doesn't have an on/off switch.
25022
It is truly silent.  Most of the time the fan is completely stopped and only when stressed I've seen that it starts spinning, but is still undetectable.

The modular design allowed me to keep everything pretty much clutter-free, although I found that the cables were rather stiff and had to constantly bend them to avoid damaging anything because of too much stress.

Really awesome overall, I highly recommend this.
3344944
Very quiet, moves a lot of air, very little power, worked reliably for me so far.  I am using this in an aquarium hood.