I think that ARG is generally 3-6 points weighted pro-Kerry in most states. Here are some examples: Bush leads by double-digits in Arizons in most polls, but six with ARG. Bush leads by 16 points or so in Georgia in most polls, but 11 with ARG. Bush trails by 4-6 points in Michigan but is down 8 with ARG. Bush has a comfortable 13 point lead or so in TN, but is only up 7 with ARG.
From electoral-vote.com the ARG results appear similar to what is currently posted with the most recent changes coming from Rasmussen. You may be right about ARG, if the weight their % based upon registrations of the population (that's usually what is meant by weighted), then their number could be wildly off. It depends upon the accuracy of the weighting. I just refuse to get upset by the day-to-day fluctuation in polling numbers.