The issue is that you have to charge it 2-4 times a day (like me who has it on 24/7). If you don't mind it becoming a "wired mouse" for 3 minutes while it is being charged by USB, then it is the perfect mouse.
However, if you are gaming and it starts to flash red during a session (will you even notice it?), you have to pause the game, plug in the USB cable into the mouse, and then get back into the game.
Genius also makes several types of gaming mouse. Once they get the charge to last longer, i think it is a great idea for convenience and never needing (to hunt for) a battery again.