Those images were in cam jpegs right? With the right processing I can get a 7d iso 6400 image to look sharp and clean....once again, just for laughs, i'm not trying to actually say the 7d is as good at high iso as the d3s, that'd be ridiculous, but... 100% crops (but the 7d has been resized to 12mp size, so to the equiv size)... One of them is the 7d, one is the d3s, from iso 12,800. The 7d shot has been ran through mah happy noise reduction action I use...
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Iso 12,800 in an almost no-light situation indoors, from 7d, after running through my processing (takes like 15-20 sec per image on mah core i5)...single dimmed cf bulb lighting small apartment "living room" (yeah, the dimmable cf bulbs still suck and don't last long, sigh

).... It is a 50% crop fyi:
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Not trying to say the 7d is a better cam than the d700, 'tis not...'tis just different. But I am saying that you can get great high iso shots from most modern cams...the much bigger things between the nikon and canon cams are simply the controls and interface. Which is more intuitive to you. If one is more intuitive to you and "feels" right, go with it...you'll be able to get great IQ no matter what.