Shutterbug reviews the Canon EOS-1Ds Mark III a 21.1 megapixel full-frame digital SLR with 5 fps shooting, 45-point AF system and 3.0-inch LCD display with Live View.
They write; “I really liked the 1Ds Mark III—what’s not to like about a 21-megapixel SLR?—but have nagging questions about reliability of any new premium D-SLR, especially one costing $8000. The $4499 1D Mark III has the same look and feel as the 1Ds Mark III and both cameras, for the first time in any Canon pro D-SLR’s history, offer simple, readable menus. For $8000 you can buy a 1D Mark III, two EOS 40Ds, and have enough cash for lots of memory cards. Why does a used 16-megapixel Hasselblad digital back cost more than a brand-new 21-megapixel 1Ds Mark III? Where’s the bargain now, medium format shooters? If maximum image quality is your main overriding question, then Canon’s EOS-1Ds Mark III is the answer.”
The Canon EOS 5D features a 12.8 megapixel Sensor (full frame), AF with 9 points, LCD of 2.5 inches, Magnesium body, DIGIC II and USB 2.0. 
The Canon EOS 30D is an upgrade of the Canon EOS 20D (same 8.19 megapixel CMOS sensor) with a larger 2.5 inch LCD (230,000 pixels) with ISO up to 1600 (in 1/3 stop increments), Spot Metering and High Precision 9-point AF system.
The Canon EOS 400D (also known as the Canon Rebel XTi) featuring 10 megapixel CMOS sensor with improved microlens array, fill factor and lower noise, EOS Integrated Cleaning System including: Anti-static coatings on sensor surfaces, Separate low pass filter with ultra-sonic vibration, Software based dust mapping / removal.
The New Canon Rebel XT (Canon EOS 350D) is an 8.0 Megapixel (APS-C CMOS sensor) DSLR with a 3 frames per second shooting rate (14 frame bursts). It has the same DIGIC II image processor of found in the high end professional ‘D-series’ of DSLRs.