Those great moments include:
- The Doctor keeping a selection of hammers under the TARDIS console for judicious in-flight application.
- Some nice cross-refs to Classic and New Who - especially the tantalising mention of the Brig.
- Donna's Mum proving to have some nous to her after all by smashing the car window.
- The Doctor's emotional farewell speech coming across as a lot less hokey after the scene in which Donna undermined its equivalent in the previous episode.
- And, though I don't actually want her to come back, the brief flash of Rose shouting for the Doctor on the TARDIS screen, which Donna didn't even notice in all the panic about the Sontarans, was a nice way of keeping that thread going.
But, on the other hand, I'd have liked to see more character-development on the part of Colonel Mace and Luke Rattigan (other than his rather implausible turn-around at the end), and although Ross's death allowed the Doctor to make an important point about the value of individual lives, he had so much potential as a recurring character! Even Martha's face-off with her clone seemed - lacklustre. If I couldn't have strong characterisation, I'd have liked something a bit more innovative or surprising from the plot. As it was, it seemed kind of generic - a space-filler, with nothing particularly challenging or thought-provoking that I could see.
On the whole, not actually bad... just not particularly outstanding.