I have both of these mice and they are exceptionally nice. The MX750 is cordless and MX500 is not. The reason I have one of each is due to needing to have batteries fresh for the cordless and sometimes running out. They both perform brilliantly and are both obviously optical. The optical standard for these mice is excellent for gaming. I have also had a Boomslang and various other so called gaming mice. The Boomslang is very good, however, you'll have to constantly be cleaning the parts of the goddamned thing and its a never ending task to keep it working up to par. So I shitcanned it and its sitting in a box.
