If I was a little skeptical about the principle, a few days of use have convinced me and the following weeks were finished strengthen my conviction that Apple should have thought of the magic mouse including this accessory, especially as the design is really in the line of home. I appreciate the trackpad of my mackbook but I confess to prefer the mouse as soon as I return to my office. If the Magic Mouse is not too greedy, it's always the wrong time that unleash the batteries and charger avoids you finally all these problems.
Like many, I had some trouble putting the battery pack in place. The space is running out and we are at the extreme limit. I must have had some cold sweats, I was afraid of damaging the beast. Being on the move regularly, I did not want directly connect the charger to the Mac (strongly the day the son disappear for good) So I opted for a connection to a small charger (iPod / iPhone). This allows to charge my smile quietly during my absences or night. A real comfort.