Great stuff, from a golden age of childrens' television drama. It's spooky, dark, funny... I don't think something like this would get made for kids today. It'd end up watered down by committee, and some of the themes would certainly raise a few eyebrows. Take a look at "Dark Season" as well, which is the spiritual predecessor to this, albeit somewhat lighter in tone.
Shame 2entertain couldn't have knocked up a couple of episodes' worth of commentaries with writer Russell T Davies, mind you - he's so eloquent and forthcoming in his other commentaries that it would have been fascinating to hear his thoughts on the early years of his writing career before he went on to hit the big time with the likes of Queer as Folk, Casanova and, of course, the spellbinding revival of Doctor Who.