To The Death is a moderately satisfying end to the fourth season - taken on its own terms, rather good, though not quite as good as I was hoping for. (Then again, most Who finales leave me feeling that way.) It wraps up the story of the second Dalek invasion of Earth started in Lucie Miller, with much drama, death and destruction.
Further discussion requires SPOILERS.
I'm not going to go on about this at great length because beccaelizabeth has already done so. (And for a more positive and also spoiler-filled take on the season as a whole, see Reality Checkpoint.) But I felt that the powerful dramatic impact of Lucie's death - as ever, superbly conveyed by Sheridan Smith - was actually weakened by also exterminating Tamsin and Alex. When Adric was killed off back in 1981, it was as if the show was saying to us, "Look what we can do!" And BF are clearly trying to emulate some of that (note that Lucie dies in almost the same way as Adric, isolated on board an exploding spaceship). But by killing off their own characters and leaving the BBC's characters alive, Big Finish are saying something more like "Look what we can't do" - the Doctor (well, obviously), Susan and the Monk must all survive. True, each has lost a loved one, and is in that sense forever changed; though I also felt that this was a bit flawed, because as beccaelizabeth points out the Doctor doesn't seem to be mourning Alex much, and for my own tastes the Monk mourns Tamsin rather more than I'd have thought consistent with his character. (Myself, I won't miss either of them.)
wwhyte pointed out somewhere, and I can't find it right now, that Caves of Androzani works far better than Logopolis even though Logopolis is about the end of the universe and Caves of Androzani is about a sordid drugs and guns smuggling operation. In this season, I thought the most successful play was the very first, Death in Blackpool, about a simple family drama (where the awful family secret is that one of the family happens to be an alien). Sometimes small is beautiful.
Surely there is also a fairly major continuity problem? (Though sometimes problems are opportunities, I suppose.) In To The Death, the Doctor clearly remembers the events of Patient Zero; but my memory of Blue Forgotten Planet is that Charley zapped all the Sixth Doctor's memories of travelling with her. Or am I wrong on that point? Might go back and listen to that sequence again while waiting for next month's releases. Though I have the new Gallifrey series to get through first...