Not suitable for quick and accurate work

The mouse is immediately noticeable because of its unusual shape. She is very good in the hand (gloves size 10).
But that was for me already the pluses.
Despite Microsoft mouse software installed, the Zeiergeschwindigkeit did not adjust to an acceptable level for working with two screens.
The accuracy of cursor control is unsatisfactory. Selecting and marking the texts etc. device so the patience and gambling.
The Windows key does in Windows 7 do not really mind.
The Back button is not worthy of its name, as it is the key hardly noticeable and take. This hand cramped easily, making the whole aforementioned ergonomics naught.
As a final point I's criticisms, the surface of the thumb rest, which gives a slightly sticky feeling.
Conclusion: For me, a bad buy.