The
G9X for Call of Duty: MW3 is a nice bit of officially licensed
MW3 hardware, but the
G9X is a nice mouse, with or without the license. There are several ways to tweak the
G9X to suit your needs, from two interchangeable grips to a modular weight system to allow you bulk up your mouse if you find the
G9X's stock weight to be a bit light for your liking.
The two grips are called "Performance" and "Wide Load." Performance is thinner and has a very thin ridge for a thumb support and features a somewhat rough grip to help your fingers stick in place during the action of frantic gaming sessions. The Wide Load is more built for comfort, with a wider thumb support, a little wider body in the palm area and a smooth, rubberized satin finish. Since it's wider on the left side, the Wide Load grip features an extra Teflon pad on the bottom, to help keep the G9X sliding smoothly. Personally, I found that when playing Call of Duty: Modern Warfare 3, I preferred the Precision Grip, since the textured grip helps to prevent any accidental slippage of the mouse, but I also found that I liked 18g of weight added, as well.
The G9X features a "Microgear" precision dual-mode scroll wheel mechanism, which works well in your choice of free-scrolling or incremental mode. However, the button to swap modes is located on the bottom of the mouse, and while it makes it nearly impossible to accidentally change the mode, it also makes it impossible to rapidly swap back and forth between these two modes while in a game. If you have a preference of one way or the other in the games you play, this is fine. If you find that you often want to switch between free scrolling and geared, however, this won't be possible with the G9X.
The G9X's buttons are programmable, and you can save up to five different profiles in the mouse. To customize the profiles, you'll need to install software from Logitech, but once the G9x has been programmed, you can take it with you to another machine and use its internally stored profiles without having to install any software on the new computer. This is a handy feature for gamers who like to customize their mouse for games, but who may play from time to time on a public computer, at a friend's house or in other situations where you can't (or shouldn't) install software on the machine.
And, although it's primarily a "bling" thing, as opposed to a functional customization, you can customize the indicator LEDs on the G9X, selecting from 204 different possible values.