Summary: I own/use the G700 (>1yr) but i have read about similar left-click issues with the G700s. This suggests that this is a recurring problem with this series of Logitech mice. The problem is when i left-click it doesn't register unless i press hard or press close to the front. Maybe it's just old. That said, the user-friendliness and features of the G700 (which are almost identical to the G700s) are very satisfying.