I have a g500 and while i have not had the others, I can say that I will never ever need to upgrade, this mouse does the job without a premium price, it also comes with a weight kit you slide into the mouse to make it heavy or really light however you like it. I have mine heavy and love it, very smooth and super fast and accurate. I think newegg has 1000s of reviews for the mouse. but always check the others too. good luck.
forgot---you can change the mouse speed on the fly with buttons as well. really nice feature. the mouse wheel can be changed to click or be smooth and the wheel will click side to side as well.