For starters, I would like to say there is no need to test this cooler with the secondary fan they had shipped to me. I did do the testing for the numbers, and while the fan is even less noticeable to the ear, the performance of the EFZ-120HA4 goes down. To give you a basic idea, while the cooler only shows a 1.1 degree difference at idle, that gap move to 2.4 degrees at load. Now while these are still acceptable numbers for such a silent cooling solution, I seriously think it isn't even a choice worth considering. I say this since SilenX included a fan controller and you can set the speed at its minimum, and get very close results as the IFX-74-09 produced. Allowing the fan to work via PWM is the better choice because even at a full 2000 RPM, this is a silent cooler!
I mentioned that we had already seen a variant of this cooler before in the HP-1216 from XtremeGear. Back then, silence wasn't the main drive of the design, and the fan included then was rated a bit lower. This time around SilenX makes sure silence is the key, and even beats out its predecessor in both temperatures and noise levels. Performing averagely in the temperature range isn't considered a failure here in my mind at all. Every cooler around the SilenX, let's say the five above or below in the listing, most will make your ear go numb under normal gaming. With the EFZ-120HA4 this is definitely not the case.
The second biggest selling point of the EFZ-120HA4 is its price tag. I'm glad to see that you can get both silence and good cooling efficiency in a cooler that sells under that magic $50 mark. Silence to me is of utmost importance, and is most of the reason I went to water cooling in the first place. Coolers like this SilenX EFZ-120HA4 offer a great base unit that is very efficient at ridding itself of heat, and shipped with one of the quietest fans I have ever personally tested. Considering how wide spread the competition is right around this cooler in our charts, it comes in at, or very near their pricing, while in my mind offering a much user friendly choice of fans. For around the $40 USD price point, I have to say this is a very viable solution to cure the loud fan overclocking blues, and still have money left over to buy something else.