Martha in general was pretty cool throughout, including her (temporary?) departure, and her links with the real world. The devastated Earth was well done, though, you know immediately that this means that the cast just have to find the Reset button and press it.
I did like the Doctor/Master relationship, and the Doctor's devastation at being the last of his people again, even though I am Old Skool enough that I cannot really believe it is the Master without a beard or a decaying face.
The Doctor-goes-all-glowy bit is, IMHO, actually a homage to the end of the Pertwee story The Mutants, where the same effect is tried (not on the Doctor but on another character) and done really really badly. Several other Pertwee-era homages, mainly to stories I haven't seen (Claws of Axos, Sea Devils).
The Doctor-turns-into-Dobby-the House-elf bit was, sadly, rubbish; and the Master keeping Martha's family alive on the off-chance that she might show up doesn't make sense.
Jack didn't get much to do except turn into the future Face of Boe, did he? And Mrs Master did hardly anything except shoot her husband. Waste of good characters.
Well, here comes the Christmas special.