... About the many reviewers complain (especially after the "re-awakening" from sleep mode), joined me also. This can be under Windows 8.1 but pretty easy fix: Control Panel - Hardware and Sound - Device Manager. In Device Manager, double-click on the Bluetooth icon. In the following submenu double click on "Bluetooth device". The last tab "Power Management" before the check mark "computer to turn off to save energy, the device" Remove. After Ok and reboot the problem should be gone. This should, incidentally, also work with other Bluetooth mice.
Otherwise, I think the mouse very well done. Clean locking function of the scroll wheel, which can also press the left / right (eg. As for lateral scrolling), useful Windows key with vibration function, but most impressed me the battery life (still have the first set after several weeks, and I several times forget the mouse off at night!). Only the glossy surface would not have to be for me, but without this it comes with modern appliances so obviously not. Overall, a successful product.