Logitech - G309 Lightspeed vs Logitech - MX Master 4

The G309 Lightspeed is the clear pick on raw spec strength, leading by 33.2 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.

Pick the G309 Lightspeed if you carry the device everywhere and weight or thickness has been the deciding factor before. The biggest gaps in its favor are polling rate, max dpi, weight.

Pick the MX Master 4 if you care most about battery and buttons. Its strongest claims are battery, buttons.

Both ship with comparable wireless, so those specs don't separate the two — focus on the differences below.

Bottom line: the G309 Lightspeed is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.