Yeah, when I played Call of Duty online with my ball mouse I could never get a accurate sight, but with my MX518, the speed and precision was so awesome...I increased my kill ratio so much.
i paid $70.00 for my MX510 in august because i was fed up with buying cheap mice that didnt work fast enough or that would glitch on me. i figured pay for a good mouse now and i wont have to for a while, or i can just keep buying cheap mice that add up in price over a while