Comfort 7

Suffering from tendinitis in his wrist, I acquired the Microsoft Natural Wireless Laser Mouse 6000. And I must say that it relieves a lot.
The much more natural hand position "is learned" very soon. The adjustment time is very fast. And return to a normal mouse is really not enjoyable.
This mouse is very precise, almost too much, and very responsive. It takes a little time to adapt. I used to picture editing and CAD and I have no problem.

Except for very small hands, I recommend the use of a mouse pad with wrist rest. In the long run it is more annoying than anything else.

For the rest of autonomy is good (more than a month without changing batteries), the supplied software is well done, the buttons are responsive and pleasant, not too hard.

The two downsides that I would highlight is the cumbersome cords receiver (USB bundle would be better) and central-click (on the wheel) difficult to differentiate from the other two clicks of the wheel (scrolling) and too hard to operate. I finally set up a thumb buttons as middle click.