Installation & Testing:
I've found all the Xigmatek installation manuals to be very easy to follow, and the same applies for the one included with the Gaia. Xigmatek's mounting system is very strong and secure and has a very similar design to the mounting system of the much more expensive Noctua coolers I will be testing the Gaia against today.
Due to the requirements of installing the included CPU backplate, you'll want to completely remove your motherboard from your case when installing the Gaia (unless you have a backplate cutout in your case). Leave the fan installation for last - I learned the hard way that installing the fan before the cooler will only impede the finger nuts that need to be tightened later (I ended up removing the fan and trying again).
Due to the impressive performance I've seen from the Xigmatek Loki and Aegir coolers, I'm going to be testing the Gaia against the same Noctua NH-C14 and NH-D14 coolers. Both are worth over double the price of the Gaia, with the NH-C14 being worth almost four times as much.
Testing will be conducted on the system outlined below. Tests will include an idle temperature measurement, taken after 30 minutes of system idle, and a load temperature measurement taken after 30 minutes of Prime 95 stress testing. I will run two tests - one with my motherboard on 'standard' PWM mode, and another with PWM disabled and the fan running at full speed.
To start, I put the Gaia against the other Xigmatek coolers I have reviewed recently; the lower end Loki and high end Aegir. Based on it's price, the Gaia falls right between both the Loki and the Aegir, and it's performance also illustrates that, falling right in the middle on both PWM and non-PWM tests.
Looking at the idle temperature test, the Gaia falls into the lower half of the chart in comparison to the coolers it was tested against. Only one cooler, the Xigmatek Aegir, managed to achieve a lower idle temperature than the Gaia. This helps illustrate the advantage of the thick 8mm heatpipes found on the Gaia, and shows that the extra pipes on the Aegir really do benefit it's performance.
Looking at the load testing, this time the Gaia fell more into the middle when compared to the same group of coolers. However, this is still great performance given the fact that all the coolers around it in the chart cost two to four times as much as the Gaia.
Noise levels of the Gaia were also very reasonable - when PWM was in use it was barely audible over the rest of my system (except when it would speed up a bit under high load). With PWM disabled, the Gaia did become noticeable above my other coolers, but still was not annoyingly loud.