4 out of 5. Almost a 5. Both Smith and Coleman did a great job. The guest characters felt like real people. High marks for the creepy atmosphere.
I loved the theme that things aren't as scary once you have more information. We saw that with the "ghost", which was really just a lost relative. We also saw that with the beast, which just wanted to be with its loved one. When the Doctor said, what's the opposite of "ignorance is bliss", my first thought was "fear".
It wasn't perfect. I was skeptical of the voice operated TARDIS or the fact that it could save the Doctor herself. He'd never be in danger then! Also, the whole love thing tying the universes together was a bit too emo for me.
Nice shoutout to Metebelis III, just wish that Smith would've pronounced it correctly!