This fan fits very well within my PC case, it is very quiet and cannot be heard over the other fans in there. Every now and again I get a waft of hot air as the fan increases speed and cools the system case down, however the rise in noise is indiscernible. The speed control of the fan depends on whether your motherboard supports this and you have the correct plug available. The fan still works admirably even without this feature.
The power connector is taken from the CPU fan plug, which can piggy back several more fans of this type (PWM). This not only reduces noise but also power consumption, deliverying both, when the system is being used to a high degree.
For the cost, it represents excellent value for money.