Depends whether you'd be watching for other elements despite an utterly incoherent plot? Eleven and Clara play off each other beautifully when they're not being co-opted into pushing a turgid and under-explained series of events along; Clara plays beautifully off the little girl guest star; we get some backstory and characterization stuff for her; the CGI and prosthetics work is A+++ spectacular. But I can't get over how awful the plot was and how many delusions it had of being amazing.

Really I think what needs to happen is for the Beeb to knock a zero off the show's budget and decree that the showrunner can't have any side projects. Because it's arguable that Torchwood sank RTD's writing on Who, and I suspect Moffat is phoning it in and not developing any of his plots properly because he's stretched thin with Sherlock. And if he wants to be able to give us more aliens and planets, great, but it seems almost as though the BBC wrote him a blank check for the 50th and he's blowing it all on spectacle and bad Photoshop promos to cover for the writing.