An outlier in PC gaming, SteelSeries' gear won't outglow Chernobyl. It's unassuming and utilitarian, like ThinkPads. They take themselves a little too seriously. But Xai is possibly the best ambidextrous gaming mouse I've ever used, despite the ridiculous HD gimmick.
It's $90, both MSRP and on Amazon.
I generally don't like ambidextrous mice. SteelSeries says they spent three years researching the ergonomics on Xai, and while it sounds crazy, it worked. The form factor is so good it feels almost like an ergonomic mouse. Bucking the trend of growing fatter and more bulbous (have you seen some of Microsoft's mice lately?) for a more streamlined, average form factor, it's an amorphous enough shape that most people will like, and no one will hate (or, conversely, truly love). The one flaw is that you're going to hit the two periphery buttons that are on the opposite side of your thumb whenever you pick up the mouse to move it, so I wound up disabling them altogether.
Xai has a monochrome LCD carved into the bottom of its ass, which sounds excessive, but it's actually quite functional: You can adjust any setting, and any of your five on-board stored profiles (which includes macros, CPI settings, etc.), directly on the mouse (bye bye, crappy mouse software). It's supremely useful. Though if you're doing more than switching from one profile to the next, you'll want to wait until you're in between matches, otherwise you're gonna get killed since the whole process of saying, changing your CPI count to slow down or speed up the mouse can take up to 30 seconds.
An issue, though, is that you only have immediate access to two CPI settings—the triangle on top flips between two alternate CPIs per profile, meaning if you want to cycle through several different speeds, you've gotta turn the mouse over and switch to a whole different profile, so if you're an aggressive mouse speed switcher (like if you're a serious sniper), that could be a dealbreaker.
There is a certain amount of spec horseshit you're swallowing with all gaming mice, most commonly couched in terms of dots per inch. SteelSeries attempts to differentiate by more precisely referring to counts per inch, which is basically the same thing—the number of increments the mouse can read in one inch of movement. Real world—well in gaming anyway—it basically translates into how fast you can turn or move your cursor, which speeds up as you ramp up the CPI. As you can imagine, the speed gets progressively more pointless, with the current "standard" of 4000DPI being about as useful as tits on a boar. Xai's money spec, if you will, is that it processes 12,000 frames a second at 5,001 CPI at movement speeds of 150 inches a second using a 10.8MP "high definition" sensor.
Guess what? I didn't test that while playing Call of Duty: Modern Warfare 2, Left 4 Dead 2 or Team Fortress 2, because no one moves their arm 150 inches a second. I will say, though, it tracks as well as—though not noticeably better than—any current generation gaming mouse, both on regular pads, and the 9HD special "HD" gaming pad SteelSeries has released for it.
If you want a gaming mouse you can use with either hand, I'd say you can't do better than Xai, though I might wait until it's a little bit cheaper. Also, I wish they'd drop the stupid, meaningless "HD" spiel. It's a mouse, not a TV.
Awesome ergonomics for an ambidextrous mouse
You can change any setting directly on the mouse
Changing settings on the mouse is a little slow
The HD thing is dumb