Mad Catz Rat Series Mice Comparison between version can be found in this link at the bottom of the page Basically, each version of the Rat comes with a different and customizable DPI which ranges from 3200 DPI to 5600 DPI. Polling Rate from 500Mhz to 1000Mhz. Tracking Speed from 1.6 m/sec. to 5.4 m/sec. Acceleration from 20G to 50G. And from 5 buttons to 7 buttons. The most notable feature are the programmable buttons and the Precision Aim Mode which actually slows down the cursor speed so you can snipe better. Also worth noting and the main selling point is the ability to adjust the Rat's 5/7/9 to fit the size of your hand. You can adjust the length of the Ra to suit your hand size. And, you can adjust the Thumb Panel of the R.A.T. 5/7/9 which moves forwards, backwards, and pivots outwards, for better comfort. Video 1 in the middle of that page. Video 2 but you need to click on the Play Video Button.