I've had one of these for about a month now. While it is not distinctly a "gaming" mouse, I am not exclusively a "gamer" either. For a mouse that does everything VERY WELL, this mouse is well worth the hundred bucks or so I paid for it. It is easily the most comfortable mouse I've ever used. I pretty religiously used a Logitech M510 for the longest time. Several mice at least, but I won't be going back at least not for my main system. This mouse is a huge improvement over almost any other mouse I've regularly used on a daily basis. It is extremely precise. The freewheel feature for the scroll wheel is fricking awesome, no more scroll, scroll, scroll, scroll to get to the top or bottom of a page. Just "flick" and it's at the top of even very long pages. The thumb wheel is much better than on previous versions as is the placement of the two thumb buttons. Overall, an excellent device.
My only complaint is that I think the thumb wheel and the two buttons need to be about a quarter inch lower down the side of the mouse, aside from that I really can't find anything to complain about at all.