Pros: Moves a lot of air, especially at full speed. The included hardware allows for mounting in 12cm holes, 14cm holes, with noise dampening silicone inserts or the threading fan screws. Two adapters to control rpm and noise. High quality product. Manufacturers included information very informative.
Cons: After removing all other fans in my case, including the ones in the power supply and video card, I was left with only noctua fans, four of these, and two of the nf-p12. I kept ruling out noise after noise, only to be left with the fact that these fans, while more mild than the power supply and video card fan, do indeed make their fair share. I can unhook one of the p12 and not notice a noise drop, but unhooking one of these is noticeable. I run these at ultra low nois...
Summary: At the highest (no-adapter) setting, the fan isn't exactly quiet, but probably quieter than other fans moving that amount of air. Slightly audible at the lowest (700rpm) setting, but better than any other 140mm I've tried. I'm using two 140mm fans on the top of my case, so the lowest setting is fine.
Pros: Solid craftsmanship, quiet at the two lower settings.
Cons: If you're mounting this on a 140mm slot, you'll need to pick up your own washers and bolts. The screws it comes with don't fit the adapter holes very well (need to be placed from one side). Also the adapter clips don't go on very securely. To fix this, I used the silicon mounting doohickys in the 120mm holes, which held the clips on firmly, and used my own washers and screws to mount the 140mm holes. Worked great.