Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: I tested these fans on Corsair H80i's radiator and it was better than Corsair SP120, but will it be better to use as case fans also? comparing Corsair
Document: Also, I know that some people aren't very fond of the color scheme that Noctua uses on their fans but don't let that fool you because this is an excellent fan. I have had a lot of awful experiences with other fans but the fans from Noctua have never let me down. You can also use this fan on a radiator and it will make a big difference over the stock fans that come with the radiator.
These three variations are the new fans from Noctua and they are part of the S12A series fans. According to Noctua, they are 8% better than its predecessor thanks to the many new features such as the anti-stall knobs and the AAO (Advanced Acoustic Optimization) that can drastically improve the airflow/noise efficiency of your case.All three variations of the S12 series fans come with a 6 year warranty and with a MTBF of 150,000 hours. They also use Noctua's SSO2 bearing with metal bearing shell.
The best case cooler i had, it's quiet you even notice that he is there. I could reduce a lot the noise of my desktop.i recommend it. Also buy a Corsair H80i Water cooler and replace fans to Noctua F12 or P12.
Been a Noctua advocate for about 5 years now. Wont use anything else if I depend on it. I switch out all of my case fans with these cool blasting beauties, as well as, using their CPU fans/ heatsinks. I consistently get as good or better cooling as my buddies using middle of the road liquid cooling systems (of similar price point), but they are ohhhh soooo reliable.
The fan can work great to keep your CPU cool or you could use it with a radiator or just as a regular case fan.The cable of the fan is rather short, but you usually don't need a long cable if you're using it with a CPU cooler. The short cable is good for this instance.
was very pleased with this fan, ordered second one also for radiator push pull for graphics card liquid cooling project, can hardly hear them run unless they are at full speed which is seldom. would definitely recommend Noctua fans for any project or replacement,
I have nothing but Noctua fans in my case! After trying every fan out there (Corsair, Coolermaster, Cougar, Thermaltake, etc) Noctua always wipes the floor with them. I have an Corsair Hydrocooler H60 and with the stock Corsair fan my CPU temps at idle were around 25c but with Noctua fans its around 16c! Don't buy any other fan if you want maximum cooling!
So Quiet. Night and Day difference from the the stock fans that came with my Corsair C70 Case. Noctua you rock!! !
I ordered four of these to replace the six year old fans in my full size Thermaltake case while doing a computer upgrade. Along with this upgrade, I decided to also get the Noctua NH-U12 CPU heatsink and an additional Noctua NF-F12 fan for the heatsink. So six Noctua fans in total. There are now only two that haven't been replaced.
I was looking for a way to quite down the case fans in my pc, which I use in a small room. I switched out three case fans with the Noctua's and noticed a huge improvement. Installation was easy and the 4 pin design allows the mother board to keep speeds down when extra cooling is not needed. Even at higher speeds, the fans are still quiet. The main noise heard now is the hard drive.
Answer: According to the description this item is a 'medium impedance' tweaked fan, 'high' rating being for radiators and heatsinks that impose a high restriction to air flow, whereas 'low' are optimized for cases. So this model is a compromise, designed to satisfy either situation. Those variants a few dollars more seem to be specifically for cases and are supposed to run quieter.. but if you're happy with the ones you have why not try them in the case.. all this marketing hype has consumers second guessing and diverted from whatever really matters.Maybe someone has a bench review somewhere with numbers for an acoustic comparison, though  of course the manufacturers blurb has summarized the results. Sorry about my dull answer, hate this technical stuff- and thank goodness for spell-check.