Software
The software of the RAT 8 allows for a lot of customization. You can store four full profiles on the mouse, make easy use of macro functionality and tweak the sensor, which even allows for angular correction to adjust for an angled grip. You could do a review on the software itself, so I'll just show you the main tabs here. As a verdict, the software suite seems very strong and intuitive.
When you open the software, you are greeted by the programming tab, which shows you the graphical interface to set custom commands as button binds. You can choose from among Windows shortcuts and regular keys and are able to create your own custom macros.
The settings tab lets you set CPI levels, adjust the CPI button's behavior (toggle, cycle), apply a CPI multiplier, configure precision aim, and adjust polling rate and angle snapping.
The CPI multiplier is a very unnecessary feature in my opinion as the sensor itself already allows for 12.000 CPI. If you still want a faster cursor, you could simply use Windows sensitivity to do the exact same thing. Still, you would miss every second pixel already with just a 2x multiplier, and a higher multiplier would obviously only make things worse. I don't see a single usage scenario where this would be preferable over just adjusting the CPI correctly.
Precision aim is that little red thumb button and is what is commonly referred to as a "sniper button". By default, it sets the CPI to 400 when the button is held and goes back to your default value when released. But you can configure it to do the opposite if you like, useful for games where vehicle-look speed is much slower than with infantry, and where such can't properly be configured in-game separately; I am looking at you, Bad Company 2.
The third tab is called Kameleon and allows you to adjust the lighting options of the mouse.
Lastly, you have the support tab where you can update the driver, download game profiles, and contact support, for example. You can also access the programming manual from here.