The D3x is optimized for dynamic range at lower ISO values, and rich color. It shoots great images at lower ISO levels, but when it was made, it took a TON of engineering effort in the electronics of the camera to wring that much performance out of the light-sensitive part, the "sensel". The entire "sensor" involves additional components beyond just the light-sensitive sensel. The "sensel" is what Sony manufactured. For an interesting bit of fun, compare the performance of the Sony A900 and A850 against the Nikon D3x; all three cameras used the same, Sony-made sensel, but Nikon sunk thousands of dollars more money into the electronics of the D3x. The color rendering performance of the A900 is not very good above 400 ISO; the D3x, while not a real High-ISO speed demon camera body, is still pretty decent at ISO 1600. In daylight, not low-light, it is VERY usable at ISO from 1,000 to 1,600, with very low visible noise in most sizes of images.
Nikon D3X versus Sony Alpha 900 - Side by side camera comparison - DxOMark
NEWER sensors are even better.
One of the biggest issues for Canon is that they can NOT use on-chip analog to digital conversion methods, and Sony and Toshiba can, and do. The Sony and Toshiba-made sensors offer on-chip ADC routines, which is an advantage...kind of like being fuel-injected, while Canon limps along with carburetors...
Sony and Toshiba have made huuuuuuuuuuge finincial investments into chip fabrication; Canon is still using older, now outdated, sensor fabrication technology. Canon has other business divisions to run, like the office machines division, while Nikon is the last remaining purely imaging company, and Sony is a VENDOR that has invested hundreds of millions of yen in state-of-the-art sensor fabrication equipment for their OWN use, as well as to sell to other camera makers. The main difference in the Sony EXMOOR generation sensors is the ability to "lift the shadows" without a ton of pattern noise showing up. This is what Fred Miranda's 5D-II vs Nikon D800 head-to-head comparison shows, and what Tony Northrup's Canon 5D-III vs Nikon D810 video comparison both raved about.
