I shoot a D200. The Canon FF Sensor is sweet and as far as image quality goes, both the Canon 20d and Nikon’s D200 have it but you’ll find it’s easier to get stunning color and sharpness with a Canon and the quality of high ISO shots are extremely better. Even the Rebel XT takes a sharper picture than my D200. Out of the box the D200 needs some tweaking and a fast lens to match the 20d in quality. Of course, if we were talking about the Mark II vs the D2x then I’d say get the D2x!