My Death Adder is so much better than the Microsoft Intellimouse I had prior to it. The increased resolution and sensitivity absolutely destroy it. I can now move the mouse maybe a total of 2" and cover the entire screen... if I have sensitivity at max. Likewise, with sensitivity at the lowest setting, my mouse pad basically isn't enough room to move the pointer across the screen. I have one of the side buttons set so if I hold it down and scroll on the scroll wheel, the sensitivity will either go up or down, with a small window popping up on my display over whatever I am doing.
I can be in a game, running around the map at max setting, then get into a position where I need utter accuracy for distance, and then I can drop the sensitivity where moving the mouse slightly results in BARELY any movement on screen. Upping it up a little bit results in perfect target-tracking ability with little effort.
I haven't played an FPS personally with this mouse yet, as I got it recently and have been playing World in Conflict IF I play any games at all. These past couple of weeks I've had very little time to play games due to school, because I let myself get into this position.