There will probably be some skepticism in this mouse for a lot of people; myself included initially. It seems to be less than half the price of the 'reputable' gaming mice brands (Logitech, Razer etc.). I bought it on the risk that it's a lot cheaper, but that I might be settling for something that wasn't much better than I was using before (a generic laser mouse). The reviews seemed solid on here and around the net, so I took the gamble. So far, I'm glad I did.
Performance-wise: The mouse is a perfect size and fit for me (I have long fingers, so this mouse might not perform as well for smaller-handed gamers). The maximum weight seemed right for me, and I haven't yet bothered tweaking the weights or anything (it's a comfortable weight, making it feel solid and heavy enough that the slightest shudder won't make you miss a shot in your favourite first-person shooter, but also light enough that you can move it without it becoming cumbersome). All the buttons are fairly easily in reach and feel well made, and there's a tactile satisfaction to the feel of them during use. This mouse favours a claw-grip/palm grip style of use (I use a claw-grip, and it feels pretty natural).
Modularity: The DPI button allows quick switching of a set of configurable preset DPI values from 600 to 3,600. As well as allowing setups to switch between general use and specialist sniping needs efficiently, the button glows a chosen colour on different DPI values making it easy to determine the setting (plus it looks nice). Each button except the left mouse button can be freely configured. They can be set up to represent any keyboard key, multimedia hotkey function, clipboard shortcut (i.e. copy/paste etc.), and most interestingly of all, a macro editor that allows you to script a complex sequence of actions to a single button press. I've tried it only on basic things, like setting a button up to perform a ctrl+alt+p hold and release function to act as a play/pause button for Winamp's global hotkeys. This seems to be only scratching the surface though, and it seems almost unnecessarily in-depth. There is also a '16-in-one mouse gestures' option, which allows the combination of a button hold and mouse movement direction to act as 1 of 16 different useful functions, from zooming in to scrolling etc. This idea interested me, but in practice I was a bit disappointed by the tediousness of putting these gestures into action and have given up on this function.
Aesthetics: I like the futuristic look of this mouse, from the glowing DPI button to the grating-style grip. Most importantly I like the minimalism in this version of the mouse. There is a version with flame graphics that, to me looks very tacky, like a kid's car toy or something; but for anyone interested it can be found here:
Sharkoon Fireglider Laser Mouse.
Cons: For all the praises of the software there is some glitchiness to it sometimes, as loading the configurations to the mouses in-built memory can seem to not register sometimes, or the software will crash when attempting read/write operations. The 500hz polling rate is good, but comparatively less than say the Razer Deathadder's 1000hz. This just means how often the mouse reports values to the computer, and whilst I honestly don't notice any difference, maybe gaming veterans would argue that 1000hz polling gets them that bit more accuracy. As with most products I've read a few cases of failed units, though as this is a problem with most products it's hardly a con; though something to consider anyway.