Pros: I bought this because replacing another G9X (my favorite mouse up until now) was going to be too costly. I was wary of a wireless mouse, but the included cable can be used as a permanent attachment, so I bit the bullet and thought I would try it. If wireless was not up to snuff, I would just plug the cable in and leave it. Boy, was I glad to be wrong, and have an awesome mouse besides. -No input lag in wired or wireless mode. At all. And I play at high sensitivities within a tiny (about 3.5-4 inches around at the extremes) movement area on all of the games I play. -Lightweight -Side button swapping to change it to left-handed (or just to add two more buttons on the opposite side of your thumb) -Battery life -Build quality is top-notch. The thumb buttons are not "mushy" like my G9X's -"Surface tuning" in the Logitech software -I don't use DPI switching on the fly, so being able to swap use the DPI buttons as a generic mouse button for extra functions was awesome -Free-scrolling on the wheel has its switch moved from an inconvenient spot (the bottom of the G9X) to the best logical spot (right behind the wheel)

Cons: I will have to nitpick here to come up with cons. -If you are a palm gripper, the side buttons may be just a tiny bit too far back for your liking. But we are talking millimeters here. -This is really digging, but it would be neat if I were able to pick a handful of colors for the lighting and have those cycle. As-is, you can have the full spectrum cycle, one color (with "breathing" option), or lights off.

Overall Review: It's at a pretty premium price point, but I don't regret a penny of my purchase. The G9X was legendary, but this is a worthy successor.

Pros: - Buttons on the mouse feel awesome to click. Each and every one of them. The feedback is consistent and always even. - As advertised, the tracking accuracy of the mouse is way up there above and beyond. It beats Razer Deathadders and Mambas on their own Goliathus and Destructor mats. - Once set up, transition wired-wireless is very nice, with a much smaller "offline" transition window than other wired-wireless hybrid mice like the Razer Mamba as long as the receiver was plugged (without the adapter) before unplugging the mouse. - That button right "under" the mouse wheel? That's not a real button. However, it's something even more awesome: a switch that toggles a super-smooth low-friction free rolling of the mouse wheel, or a crisp and stiff notch-by-notch rolling. - Speaking of buttons: you can, if you want, use both the right-handed and left-handed thumb buttons, and map them each to different buttons. - Mouse surface has a very clean feel, and has enough friction with the hand to comfortably move the mouse around easily with weird hand positions in the heat of the action, and doesn't scrape the hand and stays cool easily. - Extremely reliable so far; every single movement or button-press had an immediate responsive effect in the computer. - The awesome feeling of the mouse is still present after 4 weeks, using it several hours a day. - Surprisingly lightweight, with great static-moving friction differential that's even better than advertised with a quality gaming mouse mat.

Cons: - Takes a bit of time setting up the mouse properly - Logitech Gaming Software is bloated, heavy, and can even cause Internet connectivity issues (!!) with more fragile LAN connections in Windows Vista/7 setups, which has been a known issue for years. Thankfully, not necessary for this mouse to work a full performance. - Mouse3 button (by default the "back" thumb mouse button) is a little bit too small and too close to the back of the mouse for comfort with some grip types and hand sizes, including mine. For FPS games I often end up rebinding to the "forward" thumb button instead for things I used to have on this one, and use other buttons for what I used to have on the "forward" one.

Pros: -Very responsive -No wireless issues -Lightweight -Great clicks and great scroll wheel

Cons: -I'm a hybrid grip style between claw and palm. The buttons on the left seemed too far forward for me particularly but this is purely based on my hand alone, not yours. -Price is just too much for what you get, but the 3366 sensor is awesome in this mouse.

Overall Review: -Coming from a G602, I loved the way my hand fit on that mouse, however i was starting to notice some wireless issues at times and decided to see what the best of the best mouse was at this time. The G900 was it. It is a wonderful mouse, just for me it doesn't fit my hand correctly and I'm used to the side buttons being a little further back. I loved the sensor in this mouse so much that I returned it and ate the restocking fee and went to best buy and picked up the G502, which uses the same sensor but is wired, and costs about $100 less. The G502 fits my hand like a dream and I get the same great sensor as in the G900. Logitech makes great mice. I was trying out the other Razer mice in the store and they fit and felt terrible, and the clicks were soooo long. Buy the G900 if it fits your hand nicely and your grip style and you can afford it, its a truly wonderful wireless mouse just not for me. I also highly recommend the G502 if you need something cheaper, same 3366 sensor, don't mind wires, and are right handed.

Pros: Excellent sensor, clicks, and appearance.

Cons: Not really a con, but the mouse feels slimmer and longer than some other mouse, like even the G502. need sometime to get used to it.

Overall Review: I owned a lots of gaming mise over the years from major brands , most of them are from Logitech, it starts from the early Mx 300, to G9x,G500,g500s, to G502, G303,and others like deathadder Chroma, Rival, ect. I like this one the most. I have been playingCS, CS:Go for long long time. this one have the best balance of shape, performance, weight and mouse clicks. You may need sometime at first if you are from something else than logitech, some may even hate the feel of it at first, but you will get used to it, i would say 2,3 weeks, and then you will love it. performance wise, i feel no difference between wired or wireless. hope this helps

Pros: - 25 to 30 hour battery life - Wired or wireless swapping - Super accurate sensor - Light and fast - Software for tuning works easily - wide range of DPI

Cons: - The pros come at a high price

Overall Review: I see a lot of people rate the mouse low simply because they prefer the feel of a different brand or model. That had nothing to do with this mouse but rather that is your hand. Hardware wise this is the best mouse out there. If your hand doesn't like it then that is your issue :) If you like a heavy mouse...this one is light don't blame the mouse.

Pros: -Mechanical Pivot Switch to reduce pre-travel distance -Amazing DPI Light and Logo RGB effects -Hyperfast Scrollwheel -You can save up to 5 profiles -11 Programmable Buttons (fully customizable via Logitech Gaming Software) -Ambidextrous buttons and it's fully modular, whether you're right handed/left-handed -Weighs about 107G -Can last 24Hour battery life with RGB Lights/ 32Hours without RGB Lights, regardless polling rate, usage hours, and brightness/color cycle rate. -You can switch between wired or wireless mode via USB braided cable adapter -2.4Ghz USB Dongle

Cons: -Does not come with tuning weights -Shape may feel slightly narrow but symmetrical feel which is engineered to support ambidextrous control -High arch buttons is little too high and I wish it's a little bit lower to tap buttons faster -It would've been nice to have G-Shift of DPI Default Button on left side button for right handed user -Does not come with charging dock

Overall Review: Wireless click latency and motion latency was very good. In the past, wireless mouse suffers battery, latency, and the weight issue. DPI up/down shift buttons should be above tactile hyperfast scroll wheel button to easily press DPI shift buttons. That way it'll be a lot easier to improve muscle memory. I come from G502 Proteus Core, and it's by far one of the best wireless gaming mouse on the market! If shape and ergonomic is your biggest concern, you can go with simplistic wireless mouse which is Logitech G403 which is optimally designed for right-handed user only. Overall, I love this mouse a lot! In the near future, I'd love to see wireless version of Logitech G502 Proteus.

Pros: Better latency than some wired mice. 107g with battery is lightest wireless and lighter than some wired mice even. Responsive 25step scroll wheel. Omrons. Well placed switches. Battery life power saver feature, one charge can last 9 days depending on use. One charge 32 hrs no LED 25 hrs with LED ON during use. Cable doesn't have kinks and very light. Shell feels great and doesn't leave finger prints. On the fly DPI switching. 32bit ARM store 6 profiles with profile switch underneath. PWM3360 sensor is the best out there. Period.

Cons: A bit pricey. You pay for what you get though.

Overall Review: Most normal logi shape IMO to date. No discomfort with palm grip. I did not like any previous shapes for years from them until now. Don't get me wrong it's not the greatest ambi mouse but it doesn't feel as mechanical as it looks. I can't imagine going back to a wired mouse.

Pros: Solid design. Comfortable. Versatile.

Cons: none

Overall Review: I'm a gamer and I've struggled to find a mouse that's versatile enough and comfortable enough for heavy gaming. I currently have three of these in my house (two gaming, one for work). Love it