You read over and over again writer saying "Oh the Daleks are so hard to write for. They can't talk at length without sounding stupid". I think one of the things that most writers tackling the Daleks have failed to realise is that a Dalek silently looking at you is one of the scariest things Doctor Who can do. It's (SPOILER SPOILER SPOILER SPOILER) cameo in "Waters of Mars" was extraordinarily haunting for this reason.