It was frustrating, as all such programmes must be, for its bittiness, omissions, and the occasional silliness of the talking heads (including Philip Pullman saying for the umpteenth time that Susan Pevensie is sent to hell at the end of The Last Battle - a book he clearly hasn't read too recently). There were some odd mistakes from the narrator as well, such as the statement that the woman in the Mabinogion myth on which The Owl Service drew is named Blodwen. (Presumably Blodeuwedd was too hard to pronounce?) And did my ears deceive me, or did he say in the same breath that there were nine Narnia books and then that there were seven?* And of course they had to say that the myth of childhood innocence was blown to pieces by the Great War, and of course they had to illustrate the Great War (for those who might have forgotten what it looked like) with some archive footage of soldiers going over the top... didn't they?
On the plus side, China Mieville was good value, as were Francis Spufford and Will Self - and there was some lovely footage, including a generous amount from the 1969/70 Granada Owl Service. And - well, it's great they're making three hour-long documentaries on fantasy at all, so I shall carp no longer (though I reserve the right to quibble).
* ETA: Now I've gone back and checked, I can confirm that on this occasion my ears did deceive me - particularly my left one, which was full of wax that evening.