Given that Comscore argues that the raw web server data is flawed because of the same person using multiple machines, different browsers, deleting cookies, etc.

Given that Comscore argues that the raw web server data is flawed because of the same person using multiple machines, different browsers, deleting cookies, etc., that would be a pointless comparison. It isn't an independent analysis to take two different approaches to information-gathering and see who has the most accurate data when compared to the data gathered by one of the approaches. The question isn't whether Compete or Quantcast or Comscore is closest to the raw server data. The question is whether the raw server data can be used to accurately judge the number of people who visit a website. If so, Comscore's data are most likely irrelevant because they are approaching the problem in a completely different way.