Pros: Great feel, durable and well build. Doesn't feel cheep. Very responsive and buttons have a nice "click". Fits in hand very comfortably. I like the pinky button. The software is fairly easy to use and works well to set up different macros.
Cons: Back 3 of 12 thumb buttons are slightly hard to bend thumb back to reach but nothing major.
Summary: I saw the black ones were out of stock here on Newegg and ordered when they were available again. I can happily say the mouse I got is the new model which allows it to be re-flashed. But I didn't need too as it already had the latest firmware. So there are no issues out of the box.
Pros: One of the best mice I have ever used. It has all the functionality I wanted, with the precision I needed. The colored buttons allowed me to fine tune the light to match my case lights almost exactly. And the buttons are all angled differently so you always know which one your pushing without looking or requiring muscle memory.
Cons: Ok, so if you've done your homework on this mouse you will know that the first batch of these things were defective. they required a firmware update to fix but the firmware was not flash-able. Logitech would replace people's mice if they contacted there support and told them of the problems they had. The problem is the users had to pay shipping costs and often they would get the same old model back anyway because most support people didn't know of the issues... So bas...
Summary: I got this at 49.99. Overall, I have no problems with it. It didnt take me long to get used to it. All is said in the pros and cons. Definitely worth the price for its features..
Pros: Definitely a must get for MMO players. The difference in shapes for the buttons makes it easier to differentiate which of them you are pressing. Software for the g600 is easy to use, simple gui, user-friendly. ALL buttons can be reconfigured. The style and color of the light on the buttons and be set to your liking. It skates of the mouse does make it the smoothest mouse I've ever used.
Cons: For a FPS player, this might not be the best. This is meant for MMO games. So it will take some time to get used to its feel.
Summary: Chose this after my Razer Naga started acting up (left and right click buttons would double click randomly, and scroll wheel would scroll in the opposite direction randomly) This mouse is superior in just about every way. The main selling point for me is how little dirt and sweat sticks to this mouse. With the Naga I'd have to clean it every couple weeks. After 6 months this mouse looks brand new dirt-free, I've never had to clean it once.
Pros: Great build quality, Logitech software is amazing, Ring finger button is a nice bonus
Summary: Got this after my second piece of junk Naga died within months, again. Finally, a mouse for MMOs that has a use life longer than a few months and isn't some Cypress mouse-in-a-box glued to a nice looking chassis and firmware/driver written by obviously inexperienced freelancers. The side buttons are great for MMOs, especially if you are right-handed.
Pros: Lots of buttons, excellent build quality, does not die after a few months like the Naga
Cons: Software is a bit of a pain, but much better than Razer
Pros: Lets start with the fact that there are 20 buttons. The 12 button side panel is very easy to navigate. I have yet to fumble in any MMO that I play. I picked up League of Legends recently and found that this thing is overkill in a MOBA. Still have yet to use it in an FPS, but I'm sure it will perform marvelously.
Cons: I have experienced an occasional cursor jump when using the onboard memory. But I was already fully aware of that issue and I feel I should mention that I was experiencing these jumps only once in a blue moon. The simple fix is to just use the computer memory feature and avoid the onboard one if possible.