I've noticed that a user statistics balloon appears whenever my mouse hovers over a user's name. The points increase as content is posted. That part I understand, but I'm perplexed by the green progress bar and metal. What do these represent?
The "progress bar" indicates how a member "stacks up" against the rest of the site members in terms of posts (this is different than points, which is based on a formula that includes posts, comments, edits, and various other contributions around the site.) The determination of the "metal" is based on a range of posts that a member has made (again, different than points). FWIW, the three different attributions are something that has been noted and is being looked into.