Don't get me wrong based on the title of the review, I love Antec products in general, and am not doubting the quality of the product.
First thing I did when I got home was to plug one of these suckers in with a AC-to-molex power adapter, just to see how quiet these bad boys really are. I was definitely impressed in that arena since I could only very very faintly hear the fan unless I put my ear right up to it, even on the high setting. Decked out with a few of these you WILL be able to tell if your computer is on or not, but unless you are explicitly paying attention the noise level will fade perfectly into the background.
That said, the reason I say that this fan has limited usefulness is that it's cooling power vs. other fans can't even compete. I had originally purchased 6 of these on a whim to replace the stock fans in my desktop, which is in an Antec Twelve Hundred case that comes stock with 5 x 120mm TriCool fans and a 200mm fan, and sounds like a jet engine with the fans on medium or high. I had assumed I may be sacrificing SOME cooling power for the noise reduction, but wasn't too worried because the average temperature inside the computer is pretty good compared to numbers I've seen for other comparable setups. Foolishly, however, I didn't bother comparing specs until I had gotten home, which (using specs on the product packaging) goes like so:
Low - 1200 RPM / 25 dB / 39 CFM* / 1.56 CFM-to-dB
Medium - 1600 RPM / 28 dB / 56 CFM / 2 CFM-to-dB
High - 2000 RPM / 30 dB / 79 CFM / 2.63 CFM-to-dB
Low - 600 RPM / 8.9 dB / 21.5 CFM / 2.41 CFM-to-dB
High - 1000 RPM / 19.9 dB / 35.83 CFM / 1.8 CFM-to-dB
*Cubic Feet of air moved per Minute.
So, not only does the TriCool fan have unquestionably greater cooling power, but the amount of cooling per decibel of acoustic noise actually scales upward with increased RPM, in contrast to the TruQuiet model which scales downward.
So, in conclusion, these fans are definitely a no-go for a enthusiast, gaming, or other high-performance computer. However, if noise level is more important to you, whether you just like a quieter machine or your application makes it mission-critical (another reviewer was using them for equipment in a recording studio, for example), these are probably just the thing you need. They would probably also make just dandy replacements for the stock fans in most pre-configured desktops from HP/Dell and the like.