Updated review. Was playing Quakelive tonight, when I noticed I would press the right mouse button to zoom in and while holding the button down, the zoom would go in and out, over and over again. Looks like the button is already worn out, I have to press it a lot harder than normal to keep it zoomed in. I do want to say the battery life on this is amazing. I got the mouse on May 15th, I left it plugged in over night to charge, and I have been on wifi ever since. It's now over a month later on 17th of June, and the Logitech software says I'm at 24% with 15 hours remaining estimated. Holy crap!
ORIGINAL REVIEW I was very hesitant to spend this kind of money on a no frills, basic gaming mouse, but my god! I'm so glad I did!
I went from a G Pro, already an amazing mouse, to this one and my aim improved in almost all categories. Not having a cord randomly give a slight tug of resistance is liberating.
And it's so light, I feel like I'm just moving my bare hand on the desk sometimes.