1D Mark IV review

Dpreview.com actually got their act together and reviewed the 1D Mark IV. Dpreview's strong suit is a careful itemization of the features and doing resolution/noise/dynamic range tests. They are largely useless for analysis of how good the autofocus performance is. They didn't manage to review the 1D Mark III, which was somewhat of a stunning omission.

And the conclusions ? The 1D4 is a good camera, images are better than the 1D3, but not quite as much of an improvement as it might have been expected given the increased pixel count. Noise levels at high ISO are pretty good compared to the 1D3. Image resolution is better than the 1D3 but worse than the 5D2. Absolute resolution values from their tests are 2500 lph for the 1D4 and 2700-2800 5D2, 2200 for the 1D3. Sharpened/processed images from RAW appear comparable between the 7D and 1D4, but the latter clearly contain more "pop" in terms of color. There was quite a clear visual difference in sharpness between the 1D3 and 5D2 in both my tests and my general shooting images, but the gap would be very much narrowed with this camera. The Nikon D700 and D3S resolutions are around the same as the 1D3.

Link: dpreview's 1D Mark IV review
and 5d Mark II review for reference.