Mice are primarily two things, Shape first and Sensor second. You could have the best sensor in the world but if you're hand isn't comfortable you're going to say that mouse sucks. I would recommend reading a more in depth guide after this and watching RocketJumpNinja as he does reviews as a gamer and gives feedback on the stuff that's actually important. Also I will never support Logitech or Razer mice. In my opinion, they are the "Turtle Beach" of "gaming mice".

A note for DPI. Ignore it. Also you probably shouldn't go over 800 DPI anyway. Less than 1% of "professional" gamers use 1600. The higher the DPI the more inconsistencies will occur, you can read more here. While we're talking about it, don't move the windows mouse speed from notch 6 of 11 on the slider. If you would like to know why, click here.

Aside from shape and sensor there is a variety of other factors to consider.

• Overall Weight

• Button Switch Type like high quality Omron Switches.

• Software Support for dpi, macros, or any at all.

• Firmware options

• Lift off Distance

• Side Button Options. Usually mice have two, ambidextrous, or a full panel.

• Product Warranty & Reputable Brand. I've had my Cooler Master Spawn since 2011 with CorePad mouse feet, it's flawless. I've had Logitech mice die, called them and read off the serial number, and they've sent me a new mouse free no questions asked, no return of the broken one.