Compare

PROS: There are a lot of strengths for this camera. Fully automated or manually adjustable. Over 10 Megapixels. 2 sets of controls, for landscape or portrait use. Can hold 2 memory cards.

CONS: Very heavy. Expensive.

PROS: Lighter than its predecessor 1D Mark II, longer batter life, 14 bit, clean high ISO image quality, large LCD, live preview

CONS: Heavier than 5D to carry it all day long, price. Canon should throw in E1 hand strap if they charge that much.

PROS: Image Quality at high ISO (800 to 1600); 10 Frames per second shooting; reviewers rate image quality of this Canon model better than the new Nikon D3 (Mark III has tighter grain structure) at low ISO.

CONS: Coming from Nikon, the menus system is not as intuitive (not as good as Pro Nikon bodies). Also, there is a known hardware defect when shooting in warm weather and using the AI Servo mode.

PROS: Body very solid, nice designs, more features, 10fps.

CONS: Heavy, cost lot of money.

PROS: Extremely fast, very good shutter sensitivity, battery lasts more than 1500 shots, little signal noise up to 3200 ISO.

CONS: Sensor dust delete software does not work well. It is not great to use it to capture dust data then use Canon professional software to remove the blemish. It does not work well.