DxO documents their sensor testing procedure here:
as a multi-system user I have to agree with DXO guys, they are honest, much more so than DPR or any other unscientific review sites online.
The problem is that DXO's "science" is in dispute. How can you trust something that produces inconsistent and obviously incorrect results?
Perhaps they should submit their 'science' to the Journal of Irreproducible Results. They may even be worthy of consideration for an IgNobel Prize.
DxO results have been independently reproduced at various times. For example:
Your DxO link describes one of their Measurements, which as I've stated on multiple occasions (at least dozens, if not hundreds on these forums) I find generally well done and useful (except when they make errors and deny it, which seems to occur mainly in their lens tests). The problems are not with their Measurements, but with their Scores. Can you provide a link where DxO explicitly describes how their Scores are calculated from the Measurements? No, because they don't disclose the specifics of how those Scores are calculated. Nor do they explicitly describe the bias inherent in their Scores.
You can read about the methodology of their scores here:http://www.dxomark.com/About/Sensor-scores
And I describe in detail their low-light score, the score which typically produces the most Canon vs Nikon controversy in online debates:http://www.dpreview.com/forums/post/41265241
As for your 'independent reproduction,' I clicked your first link but to be honest, I stopped reading after, "For some obscure reason - sunspots or moon phase or other strangeness - photons are behaving better today, and I achieved higher FWC results for my D3's than I have before." Sorry, but independent verification of poor pseudoscience with worse pseudoscience is even less valid than two wrongs making a right.
She wrote that as tongue 'n cheek, and it actually represents a sign of humility and willingness to be open to contrary points of view, signs of a good engineer/scientist. As for her credentials, if you follow her posts on dpreview you'll see she one of the most informed technical minds for camera sensor info. To cite a specific example, she reverse-engineered Nikon's long-exposure noise algorithm, identified serious problems with it, devised a much improved alternate algorithm which was relayed to Nikon by Thom Hogan and then later adopted by Nikon in subsequent camera designs.