Since my purchase about 4 weeks ago I use the Performance Mouse MX daily. Although I forget most off, the battery lasts for about a week before the software gives me the feedback that I have to charge it again. That's all great for me. Without the lässtige cable and the tiny Unifying USB adapter makes working, a lot of fun. Even the mouse preferences are such that you do not need to change. Only the drivers for the adapter and Unifying Logitech SetPoint to change your mouse button assignment you have to download more from the Logitech support page. But then the drivers are also the same red-hot. In addition, the mouse - I suspect - Teflon feet with which they slide nearly without friction over the desk and due to their quality workmanship and not not to low mass, you have to have the feeling of craftsmanship in your hand. Top notch. Hopefully I can work with it for a long time!
Conclusion: This mouse is worth every penny. Zero compromise, long battery life, wonderful work.