Logitech's G-Series mice were some of the first in the gaming-specific space, and consequently have a long and respected history. The G5 and G7 were pretty traditional looking, but the G9 finally makes a big departure from Logitech's usual ergonomic design. Styled in black, grippy plasto-rubber and molded to a much rounder shape than the Logitech's other mice, the G9 would be difficult to mistake for a typical productivity device. The core laser engine is capable of up to 3,200-dpi, an advance over the standard 2,000-dpi engines common among other mice, which means you can jack up the sensitivity of mouse movement to pretty much unusable levels.
Gaming mice, however, are a lot more than the tracking engine they employ, and in the case of the G9, much, much more. The mouse has pretty much everything: Adjustable weight system-check. On-the-fly dpi-switching (with LED display)-check. Interchangeable grips-check. Unique adjustable scroll wheel-check. On-board memory-check. Does this make the G9 the ultimate gaming mouse? Let's see.
From a hands-on point of view, the G9 is the most adaptable mouse there is. The mouse ships with a pair of housings that clip aboard a core mouse unit. The standard version is coated in the grippy plasto-rubber Razer has been using on its mouse, and is primarily characterized in terms of shape by a wide thumb area on the left side of the mouse that benefits those who like the palm-grip style of play. The alternate housing is composed of hard black textured plastic, and lacks the thumb-area bulge of the other housing, which makes it more comfortable for fans of the finger-grip play style. Though not as ergonomically contoured as many other mice, we found the G9 plenty comfortable and easy to control.
The G9's various other features are also nice. When the external housings are removed, a spring loaded weight tray is made accessible in the G9's core unit, and is capable of accepting up to 28-grams of special metal weights. We're a little ambivalent in terms of the utility of customizable weighting, but some sensitive gamers likely know exactly how much they'd like their mouse to weigh, so it's a good feature to have. The G9 also sports an entirely unique feature in the form of its 'MicroGear Precision Scroll Wheel,' which, via a button on the underside of the mouse, can be configured to scroll with the usual click-click motion common to other mice, or roll entirely freely, which is cool. The scroll wheel itself seems to be made of aluminum, and consequently has a nice weight to it.
Almost any gaming mouse these days is capable of on-the-fly dpi switching, but a fair number don't have buttons dedicated to the task (we're looking at you, Razer). To make the feature useful, we believe dedicated buttons are key, as necessitating an alt-tab to fiddle with a taskbar program while setting up to snipe in an FPS title just doesn't work. The G9, thankfully, has buttons just for adjusting dpi, inlaid at the base of the main left-click button. Directly below the buttons an LED readout denotes the dpi selected, which is also quite useful. Though preset to red, the LEDs can be configured via software to glow in hundreds of different colors, which is also cool.
The core buttons (left- and right-click and the two thumb-clicks) on the G9 are high quality and feel good. The main buttons are shorter than those found on Razer's mice, but have an almost as sensitive click-response, which we like. The thumb buttons, while small, are very well positioned and have good clicks, which makes accidentally pressing both difficult. We have no complaints.
Conclusion
Logitech's G9 gaming mouse sports every single feature available in the field, as well as a uniquely adjustable scroll-wheel, which makes it the hardest-core gaming mouse available. Logitech has a pretty much unassailable reputation for quality, and the G9 is no exception. We were hard pressed to find any gripes with the mouse, other than its rather high ($99.99) price. Regardless, for those who appreciate gaming mice, there are no true competitors to the G9 in terms features, and its actual gaming performance is easily on par with the best of the rest of the field.