Well, I've had two of these rodents. Functionality-wise, it does what it says on the tin, and it looks good. It's a very responsive mouse. However, the with the first one I received, the left mouse button squeaked straight away. It may seem trivial, but it became so annoying (and pretty loud) I had to return it for a replacement. The second one came, without a squeak - but after 3 weeks' use, it's developed the LMB squeak again. I guess it's a design flaw. Coupled with the fact that the thumb button isn't that responsive, I'm disappointed in what should have been a fantastic bit of kit.