Bought one for work (heavy duty) in October and for the house in January. A little time to adapt to the speed of skiing. Some jumps sometimes seen when the usb dongle (very practical) is behind a tower bottom of the desktop. Using no particular pain.
For cons, the radius of the large quality defects, surprising with logitech: - The batteries expected to last 2 years have not kept 4 months in daily use (8h / day) - The click wheel stopped working after five months