Based on the comments, I have set a bounty on the 2013 questionon the 2013 question, claiming that "The current answer(s) are out-of-date and require revision given recent changes", which is not entirely correct but the closest "bounty reason".
(Now I'd just love for the bounty text to respect the paragraph breaks I included...)
Edit: I just awarded the bounty to Ben Bolker's original answerBen Bolker's original answer, although there was not as much updating going on as I had hoped for. However, Ben posted a link to some additional recent thoughts of hisBen posted a link to some additional recent thoughts of his, which he may include in his answer at some date.