Except for occasional scrolling accidentally (finger along the mouse to make a difference) has nothing really bothered me.
Thanks to small additional software is now even possible for example to use additional features (for example to replace the center button with 3 fingers touch) and the mouse has determined potential for further extensions or VL is also Apple expand the driver?
For battery life I can say little, but will then use batteries,
Bluetooth Epfang is exemplary, even at the other end of the apartment by two walls, the mouse went smoothly.
The small size is accustomed relatively quickly to play but another mouse is intended to recommend, since no click of 2 keys simultaneously.
Who the small disadvantages not mind, I can only recommend the mouse.
Supplement 11/2013:
Even after more than four years, I am still pleased with the Magic Mouse, and it works flawlessly.
The mouse has only side scuff marks, the silver paint is something from.
I used for some time AA batteries from Apple and Sanyo Eneloop, both types maintain similar long and function well (in which Apple is the battery level indicator in OS X in more detail).
For casual gaming, I've found that the mouse can be uncomfortable because it only a clickable button simultaneously when you have to press two keys at once. To this end, a classic two- (or multi-) button mouse is recommended.
Although the Magic Mouse is no longer any possibilities of the new OS X versions exploits (eg with two fingers zoom: Only with trackpad), it is for me still the most comfortable solution and Apple also has the Exposé feature in double-tap with two fingers submitted in the new OS X versions.
Although the flat shape can sometimes interfere with (not always keep optimum), but I got used to it well.