I have got a new one at work, and use it today for the first day. It replaces my G500, which I also have at home.
So far I have of course get used to the shape, the color is
very nice, the clearance of the plastics is not so OK everywhere (should be seen on the pictures), the scroll wheel seems to have its own life, and the button for the thumb is a little bit hard to press. The cable position for battery loading is on the front, so you can use the mouse when loading... I have not changed any settings yet.
And here compared to my other mice devices I use - mostly a normal mouse, then sometimes for a few hours a pen & tablet, and rarely the vertical mouse - but that one I just not used enough to get used to it. Instead - when having enough from the mouse - I always use the pen instead. Or what I did with the Logitech G500, I worked with the left hand for 2-3 hours. But that won't work now with the MX Master...
![Image](http://i.imgur.com/1eYFJco.jpg)