Mark Forman has posted tests of his Canon 5D Mk II with updated firmware, and writes:
“Now that the Canon 5D Mark II camera has manual control, I did some shutter speed tests from 1/30 to 1/4000th Second — in order slow to fast. The last shot is variable full shutter speed range on the fly during that take. I varied ISO as the speed increased and kept aperture of f2.8 to f .6 at 24mm. Also, the compression on the site is different than the camera originals.”
Click here to see tests.