The mouse itself fits in design great for X1 - am very satisfied
The mouse has connectivity issues with the Lenovo X1 Carbon Touch (Windows 8 and 8.1.). Initial Bluetooth pair works fine, but after 2-3 hours or after waking from sleep is the connection path and can not be recovered even by switching on / off the mouse or renewed search. Must then remove the mouse from the Bluetooth device manager and re-connect again - quite annoying. Whether this is now on the mouse or on the X1 I have to investigate.