I just finished watching Turn Left which was a competent episode. It has a trick which I hate in that nothing in the episode actually happened (which it the same reason I hated Hero) but it was well made and enjoyable which continues to surprise about season four of New Who. Seasons 1 2 and 3 of New who were notably mainly for how terrible they were. A good episode like Bink happened once in a while but in three season who could count the good episodes on one hand. Then Season 4 happened. Unlike what came before good episode after good episode appeared before. Eve Russel T Davis wrote a very good episode. I have never heard of a tv show this bad suddenly having a season this good. There was absolutely no warning this would happen. The Christmas episode before season 4 was one of the worst episodes of television ever made ,thought it was good for a typical New who episode. Season 4 of new who represents one of the most amazing turnarounds in entertainment history. If Uwe Bowl's next film was Oscar worthy it would not be a shocking as what has happened in season 4.
I wanted to get this out before the finale as New who is famous for painfully bad finales. But even if Season 4 hold true to form it is still far and away the best season of new who ever and no one could see it coming which makes that fact all the more amazing.