The difference between a good mouse and a great mouse lies in the littlest details that the manufacturers put into their products. On the outset, you wouldn’t really be able to tell which mouse is better if you erase the logos off of 2 sets of gaming mice placed side by side one another. For all you know, they might look very alike. In fact, these days, most mice have the flashiest designs, all riddled with plenty of programmable buttons, laser sensors and other features commonly associated with high-end gear.
The moment you lay your hands upon one and actually test it however, that’s when it all dawns upon you. At least, it does for me. I can easily detect the different DPI settings on every gaming mice that I can personally use and test. The thing about DPI is that it allows a tremendous range of user preferences to the gamer. If you think that your cursor is flying across the screen too quickly and it’s hard to aim with any precision at all, then you’d certainly do better with a lower DPI level and vice versa. That’s really what DPI is all about.
You might be struggling to comprehend the difference in the sensitivity options provided in Windows, the in-game mouse settings and DPI. There actually isn’t much, besides the wider range and more precise measurements that the DPI provides to the gamer. For instance, under Windows’ settings, you could tune the mouse settings to change the DPI from 500 intervals right up to say 5000 DPI. But, what if you’d like a sensitivity of 2800 instead? With an ordinary mouse with non-adjustable DPI settings, you’d be stuck with either a 2500 or 3000 DPI. Keep in mind that these are all just rough examples. The variance could very well be larger than expected.
The point I’m trying to make is that a gaming mouse accords to you much greater customization choices, not only in terms of the DPI levels but also setting the functions that each button on the mouse provides. Wireless gaming mice of any decent quality (http://www.gaminggearlab.com/choosing-the-best-wireless-gaming-mouse/) will usually have a minimum of 2 additional buttons. One on each side or both on its left (if you’re a right hand user). There are certain types of mouse like the Razer Naga MMO gaming mouse that have over 15 buttons on its side, but I’m not into those. If you’re any good, you’d be executing most of your in-game commands with your keyboard rather than your mouse.
It does help a little if you have additional buttons that you can map certain functions to. That much, I’ll admit, which is why I recommend getting a gaming mouse that has a couple of extra buttons besides the inherent left, right and middle mouse buttons. A wireless mouse I’d recommend for gaming is the Razer Orochi given its lightweight (though adjustable) feature. Other than that, you should be good to go!