Phil Askey has posted in depth review on Canon EOS 5d at Dpreview and wrote:

“Pros: Excellent resolution, a real upgrade for eight megapixel Canon owners (EOS 20D), Full frame 35 mm size sensor delivers film-like shooting experience, real wide angle, Very large, bright viewfinder really fills your vision, Very low noise even at higher sensitivities, About a third of a stop more sensitive than indicated, Very well implemented large buffer supported by fast CF throughput, Very well built, more robust feeling than the EOS 20D (closer to 1D build), Very fast in use, short shutter lag, instant startup, Spot metering (wasn’t available on the EOS 20D), New Picture Styles make it easier to get ‘ready to use’ results straight from the camera, Wide range of image parameter adjustment (-4 to +4 for most), Wide range of ISO sensitivities, ISO 50 - 3200 (with ‘ISO Expansion’ enabled), Huge LCD monitor with great resolution, dimmer than some smaller screens, Soft touch shutter release, Proper RAW+JPEG with immediately selectable JPEG image size, Interchangeable focus screen, Remote tethered capture software for studio work (included), Orientation sensor, Optional WFT-E1 wireless transmitter (802.11 b/g), Supplied software bundle very good; ZoomBrowser EX and DPP both matured now

Cons: Edge softness / falloff / chromatic aberrations, needs good lenses, AI Servo (continuous AF) interference banding issue (certain lenses, high sensitivities), Same old ‘CF compartment door shuts camera down’ issue, Picture Style differences between RAW Image Task/Camera and DPP, Picture Style tone curve not indicated in camera menu (contrast is an offset, not absolute), Pretty average automatic white balance in artificial light, Mirror lock-up still buried in menus (should be a continuous shooting mode option), No mass storage device USB mode, limited throughput (just 2.5 MB/sec) , No anti-reflective coating on LCD monitor, No GPS support , No built-in flash, no built-in AF assist lamp , Price premium over cropped sensor cameras “

Website : DPreview review of Canon 5D Camera