I had high hopes for this mouse as a work desktop mouse (not for gaming). I had a Logitech G500 for the longest time and that mouse, known for it's eventual double clicking issues, finally failed on me. I though this mouse looked like it would be just as comfortable so I decided to give it a try. Unfortunately it could not live up to the high expectations of the G500 and I have returned it.
The good: Its battery life is outstanding. Out of the box I never had to charge it over the several days that I used it before returning it. The wireless reception was spot on and I never had tracking issues. The mouse glided smoothly on my mouse mat. Overall response was excellent. The software and customizable buttons worked well too. Easy to program macros or predefined commands such as minimize all windows, forward/back, etc. The mouse also has a strange function on the scroll wheel where you can set it to unlock the 'clicking' mode and slip to smooth scrolling if you roll the mouse while fast. I didn't like this option and luckily it can be turned off in the software settings (initially I thought the scroll wheel was broken because it's set to do this by default and you need the software to turn it off). The issue I didn't like was if the wheel was on click, and then I scrolled fast and the click disabled, then I would have to press the button to activate the click again. Very annoying to me.
The bad: The mouse is very heavy, especially in the back where the battery lives. Over time I definitely suffered wrist fatigue from using this mouse. Also, I like to grip my mouse in a claw fashion (rather than laying my palm completely down on the mouse). This allows me to move the mouse short distances with my fingers without having to move my wrist. It's just something I developed over the years and is intuitive to me. But because of the size of this mouse, my fingers really had to curl up to hold the mouse properly, again causing hand fatigue. And for some reason, the way the mouse is laid out, my index finger kept wanting to lay on the right side of the left mouse button so clicking the left button didn't feel natural, I kept having to move my finger over to click it.
I could never get the side scroll wheel to work, not sure if there was something I was missing in the software settings. But I'm not sure I would have liked that anyway, there is a lot of resistance in that wheel and trying to move it with my thumb took too much effort. And the side buttons are not positioned well. They are behind the scroll wheel and they are way too close to each other. So to use them, I really had to bend my thumb backwards, and then feel for the correct button (top or bottom), but they weren't differentiated enough to make it easy to pick the correct one. I had to pause and think about where my thumb was, rather than just be able to click and go.
Overall, just not a mouse that fit my hand well and was too heavy. Others may enjoy this mouse and it did have a lot going for it, but I needed to move on.