I've completely rewritten my D3x review. Why, you ask? Because it became clear that the original camera I received was sub-par in more than one way. As I compared my results with other pros, I found that many things we agreed on, but some things didn't seem the same between my camera and theirs.
In particular, noise levels on my original D3x were not the same as three other bodies I've now tested against. That amp noise I saw, for example, wasn't present in the other three bodies. Moreover, when I received a replacement D3x via my dealer, it was clear that the noise levels I measured on it were better than the original body I received. This sample variation has forced me to go back and retest everything, then rewrite the review.
I've already heard from more people with problems with their D3x than I heard from people with D3 problems the first month it was out. Considering that the number of D3x bodies that have shipped is considerably lower than the number of D3 bodies that shipped in the same time period, this isn't a good sign. Let's hope that my experience and that of others I've heard from are a short-term anomaly or just a result of the higher price producing more complaints.