Doesn't matter what fantastic features it has, when a mouse doesn't fit YOUR hand or the way YOU grip the mouse, it's a thorn on the side.
Second most important aspect is scroll wheel. The wheel is the thing on the mouse you use the most often, it must not rub you the wrong way.
Some mouse, it's hard to scroll. You'll feel it after a while when you scroll all day in a day job.
〔☛ Logitech Gaming Mouses Review〕
Also watch out for mouses with slippery wheel surface and strong wheel resistance. With such mouse, it requires you to hold the mouse firmly, else you slip, or the mouse gets pushed.
for more about Logitech's spin wheel, see: Logitech Mouse with Spin Wheel
For mouse with more than 3 buttons, the button's position and feel must be right.
For 5 or more button mouses, the extra buttons don't have standardized positions. When the position isn't right, some button will be very hard to use, essentially making them useless.
If you are buying a mouse with more than 3 buttons, it's critical to check those extra button's position and feel.
3 buttons is basic. But 5 buttons is quite essential. The extra 2 buttons can be used for forward/backward browser page, or switch apps, switch tab, or close tab.
For gamer, or a programer, or digital media professional (game design, 3D modeling, video editing), you'll want 7 or more buttons. See: Why You Need a 9 Buttons Mouse?.
Most mouses are right-handed. 4th and 5th buttons are placed for your thumb, which is the best. If you are left-handed, you might shop for a dedicated left-handed mouse with dedicated shape. A left-handed mouse is much better than so-called ambidextrous (symmetric) ones.
Here's 2 left-hand mouses.
For serious computer user, gaming mouse is always better, because:
Gaming mouse often features colorful led light too, but that's icing on a cake.
Laser lets you track more surfaces, such as on glass surface or carpet. However, laser are actually worse for gaming, in general. (when you lift the mouse, the pointer will jitter.) See: What's the Difference Between Optical Mouse and Laser Mouse?.
DPI is NOT important, even for gaming. Basically, all mouses you buy today have sufficient DPI even if you have huge screen. But also, you can adjust mouse pointer sensitivity in {Windows, Linux, Mac}.
DPI is a marketing ploy for gaming mouse. The importance of DPI is a undying myth. In fact, if you are a pro gamer in first-person shooter games, you probably should use a lower DPI (⁖ 800 or 1200) and turn on acceleration. Because lower DPI gives you precision, and acceleration gives you speed for fast turn-around, dynamically controlled by you by the speed you move the mouse. See: What's Mouse DPI? Does Mouse DPI Matter in Gaming?.
Some hardcore first-person shooter gamers will tell you to turn off pointer acceleration and set DPI to high, such as 3k or 4k. Don't believe them. 1200 DPI is enough.
Many gaming mouse can set polling rate to a high number, such as 500 Hz or 1000 Hz.
Polling rate is the rate your computer receive mouse signals. (on the USB bus, on a fixed interval, it asks for each device to send signal. Thus, it's called “polling” rate.)
By default, operating system set polling rate to 125Hz (meaning, 125 times per second)
Most gaming mouse will set a faster polling rate, via it's driver software or automatically in its hardware.
Here's a table of polling rate and delay.
| Hz | milliseconds | second |
|---|---|---|
| 1000 | 1 | 0.001 |
| 500 | 2 | 0.002 |
| 250 | 4 | 0.004 |
| 125 (default) | 8 | 0.008 |
| 100 | 10 | 0.01 |
So, the question is, do you move the mouse fast ＆ accurate enough such that a delay smaller than 0.008 second makes a difference?
If you set polling rate to 500 Hz, you can see a difference, when you move the mouse across screen in a large swipe. With faster polling rate, the trail will be smooth. But i don't think it has actual effect in improving your first-person shooter gaming.
Setting higher polling rate sucks battery life.
There are many other aspects of mouse and features, but mostly it depends on person, need, preference, and choices should be obvious.
• Wired vs wireless. Wireless is convenient, but with wired mouse you don't have to worry about battery or charging. Ten years ago, wireless mouse often have tracking problems, but not today.
• Mouses differ in weight. Wireless mouse often has battery, so it's heavier. Some gaming mouse has detachable weight, that lets you adjust. Kinda silly.
Standard 3-buttons mouses works in any OS without extra software.
Microsoft's mouses come with IntelliPoint software. It works for Windows ＆ Mac. (Microsoft Windows stopped making gaming mouses around 2012.)
Logitech has software for Microsoft Windows. For their gaming mouse with extra buttons, you can use the Windows software to configure your buttons, then, those extra buttons can be used in Mac ＆ Linux.
If you want a mouse for Linux with dedicated driver software (so you don't need to setup on Microsoft Windows first), then, get ROCCAT Mouse.
ROCCAT Mouse: 10-Button Mouse with Open Source Linux Driver