I think the two ratings have different perspectives in much the same way that there are two perspectives here. For RT, the unweighted opinions tell us what an arbitrary group of people think of a given show. In effect, it is the WOM perspective. Some people look at the raw score and no deeper, while others try to make an assessment based on their experience with a given reviewer. (That experience is, of course, often weighted to the top critics but not necessarily. Just as on this board, I think a lot of people decide how much weight to give to individual reviewers (of any level) based on how consistent their opinions have been historically with those of the readers.) So I am much more likely to discount the hack from the NYPost and elevate the insights from the not-a-hack from the WashPost, for instance. At the end of the day, though, RT is likely to predict the broad reception of a film as well or better than Metacritic. And Metacritic is more likely to predict things like awards and perhaps box office and staying power, at least in non-blockbuster juggernaut movies.