I actually rather enjoyed this one, even with the anvilicious symbolism. Then again, I like stuff that deals with death vs. immortality, and the high price of getting what you want. There were also some nice moments, like reversing the polarity (callback to Pertwee), and once again having the solution be actually sonic.

I can't help wondering if each season is deliberately following a pattern (Doctor meets Companion, Doctor meets Companion's family, family distrusts Doctor and warns Companion) or if it's just sort of happening that way. If it's deliberate, there's something interesting about that; if it's just laziness I hope they break away from it soon.