SFDebris covered it a few months ago and really nailed why I didn't like it. It's a bad story filled with seams of really good ideas. I also rewatched Children of Earth a few months ago and it sadly didn't hold up. There were some great moments and the ending was bleak and heartbreaking, but there was also a lot of crap and stupidity in it. That final episode though was superb, from Gwen's opening monologue to Jack's heartbreaking decision.