There have been several threads discussing this already. Its too early to call it a diagnostic test I think, but there is now enough data to say it should be considered for all patients well enough to do it, especially if they need objective evidence of disability, or are facing issues with misdiagnosis or inappropriate exercise prescriptions. With some more confirmation and testing, then I think it could be considered diagnostic. Now I do think it probably is diagnostic, but I also think that this wont be fully accepted on current evidence, but the tide is turning.
Given the data I am not too concerned with false positives or negatives. For one thing, were the two diagnostic failures really failures, or were the patients misdiagnosed? For the sedentary controls, did the sedentary control really have undiagnosed CFS or ME?