I took the G400s to replace the Logitech (the wheel stopped responding). In my opinion, she is no better. Even more comfortable for my hand.
Pros
Excellent mouse (mid price range). Comfortable shape, palm and fingers do not get tired. For large hands (like mine). Nice lighting, a kind of soothing LED night light. Large, with a clear fixation of the scroll wheel. Easy sensitivity adjustment (just intuitive). The cord is braided, someone says hard, it suits me.