Overall image quality has improved since the D50; cameras can produce larger prints and using higher ISO without faultering. Color is subjective, but all cameras default color can be changed, or can be changed in processing.

The Nikon D5100 and D7000 use the same sensor and will output virtually identical IQ. The D7000 adds more rugged construction, a brighter viewfinder, a more advance autofocus system, and more external controls. The Canon 60D rather slots in between the two Nikon's, leaning closer to the D7000.

The D7000's 18-105mm kit lens is better optically compared to the Canon's 18-135mm kit lens, but obviously has a little less focal length. The D5100's 18-55mm kit lens is also very good, but not as versatile.

Another camera worth looking at is the Sony A65.