I don't read all the opinions all that close on any of these reviews. I look at many, and kind of take note of anything important to me. I'm not sure if they are or not, but let's take a step back here.
1) Sure it would have been better if Nvidia had not given them the program to analyze the data, but they had tried unsuccessfully to create one of their own. Nvidia decided it would be great if they could succeed at their goal and provided them with their tool. The tool is accurate, no one has ever claimed it wasn't, so I personally think it was worth using as there is nothing better out there. Does it really matter that Nvidia gave them that tool if it is accurate? (I realize that it does give the possibility of showing bias, but it would have been a shame had we not known. I'm glad it surfaced).
2) Before they stopped using it, they had many reviews stating that once you get under X ms, it really didn't matter and both companies were beating the desired results. At some point, it is reasonable to assume that the work no longer made sense, as there was nothing worthwhile to report.
It is quite possible they are biased, but even someone unbiased would have taken the tool in their situation, as their own tools were not good enough to analyze something they thought was important to study. And after months of uninteresting data, it also made sense to stop analyzing it. There were a few months of good data from both companies, making that time spent a waste.
I'm personally going to make sure to see that site regardless. They are more likely to show something other sites will not, and that may be important to me when I make a decision. Alienating that site may backfire on them. Just as Nvidia giving the FCAT tool has backfired on Nvidia. Had they kept their mouth shut, AMD never would have fixed their CF issues, and Nvidia would have continued to receive free praise about superior multi-GPU performance.
In the end, I'm not too concerned about it. There are lots of sites out there and I'll browse several before I make my choice and I will visit those sites many claim as biased, as often time they are labeled biased because they notice things others did not report and might be important to know. The ones people deem neutral often ignore the flaws that I think are important. This goes for both companies.