Reflecting on this episode, the thing that stands out for me about it was how Russell T. Davies it was. It could almost have been written by RTD, and I wouldn't be surprised to find it was originally intended for his era: the modern setting on a council estate, the cuckoo alien, the physical manifestation of emotion (the distress call through time and space) and in particular everything being resolved by wuv.

I wonder what we would have made of this had it been near the beginning of the 11th Doctor's run? The Moffatt/Smith style is now stamped with such confidence on the show that a script like this can be taken on its merits - not that any of the parallels are I've drawn are by way of criticism: RTD has written some of the best Doctor Who even if this format has sometimes failed, too. But I think some of the strongest elements of the episode were due to the visual style of the last couple of seasons, and in particular Matt Smith's fascinating alienness, which is just so extraordinary in this kind of context. That helped lift the opening of the episode and mitigated some of the weaker elements like the stock neighbours.