I really do feel like this mouse was designed from the ground up just for me! I have always been a fan of thumb buttons since my first mouse that had them, the original Microsoft Intellimouse explorer. This has 4 thumb buttons, that are easy to use, and in the perfect spot for me. All of the buttons are easy to access, and fully programmable. Overall, it it very comfortable, and I love the thumb rest. This is the mouse I would have designed for myself.I use it for playing World of Warcraft, and while the game does not directly recognize any buttons beyond the first 5, you can program and macro the rest of the buttons, giving you very quick access to lots of stuff.I also really like the scroll wheel. Being able to switch between free scrolling and normal scrolling is great. I like free scrolling while web surfing, it lets me get to the bottom of a page very quickly, but free scrolling sucks in games, because your camera view can be accidentally moved very easily. The button for switching scrolling modes is right behind the scroll wheel, making mode switching super easy and quick. My cordless 620 had the mode switch underneath, which was a bit of a pain.The build quality is excellent, the rechargeable battery included is of the best quality, and the finish texture gives a secure grip.I tend to be very critical and picky, but so far the only slight cons I have with it is, its a bit heavy. It does move well though. The price is a bit steep, but I have no regrets so far. 

Question: Where did you find the best price for headphones?
Answer: it it very comfortable