The medium quality settings provides considerably less detailed visuals. As a result average frame rates skyrocket with both the GeForce GTX 480 and Radeon HD 5850 averaging 118fps followed by the HD 6870 with 116fps.
At the opposite end of the graph we find the Radeon HD 5670 which was just able to provide playable frame rates at 1680x1050, but it's still not bad for a $80 graphics card. The Radeon HD 5750 was considerably faster averaging 61fps, while the GeForce GTX 460 was much faster with 83fps.
Increasing the resolution to 1920x1200 didn't change much, almost all graphics cards with the exception of the Radeon HD 5670 were easily able to deliver highly playable performance.
Even at 2560x1600 the Radeon HD 5850 averaged 78fps, while the HD 6870 also managed 74fps. Performance was fairly solid with all cards tested except for the budget-minded Radeon HD 5670.