The Shakoon Silent Eagle 1000 is truly silent fan. Thats because its a 80 mm fan rotating at less than 1000 rpm. The amount of air this fan pushes out leaves a lot to be desired. For the price, which I believe to be expensive for what it does, this product seems over engineered. The golf ball style texture on the admittedly good quality blades and the flanged inlets seem a bit useless for a fan which essentially achieves its unique selling point of silence because it spins very slowly. The faster 2000 version may be a better buy. So far i have only seen use for this fan in parts of my PC where there might be recirculating air, or to stop flow of air in the wrong direction on the rear exhaust vent. You can feel a slight breeze coming out from the fan when flow is not obstructed (think about exhaling slowly), but its pretty much useless for any type of active cooling. It will need to be supplemented with more powerful fans. Nonetheless it may have its uses such as providing some air over passively cooled components which are silent anyway, but for most people, buying a more powerful (and probably cheaper) fan and using a fan speed controller to get the noise down might be a better option.
If you are looking for a powerful and high-performance but concurrently noiseless case fan, you will find a so far uncommon, however well thought-out solution in the Silent Eagle models: In comparison with conventional fans the unique surface structure of the Silent Eagle allows an improved airflow - at the same rotation speed. This principle is based on the surface texture of a golf ball, which helps to reduce air resistance and turbulence, resulting in particularly quiet operation while maximizing airflow volume. In addition, the rounded edges of the Silent Eagle's frame offer a markedly improved air intake.