I enjoyed it. A lot of unanswered questions, such as why aren't the planes being left behind in the Earth's orbit as time goes on around them, but it sort of worked as an idea. It's pretty obvious that the Doctor is not going to let Davros die in the past, that won't actually help much (unless he wants to see the whole universe eaten by paradox monsters), so I'm guessing that he's going to save the boy, try to improve his life etc., but fail miserably.
As for Missy, she's obviously used the vortex manipulator to rescue herself, Clara, and the TARDIS, but the details should be interesting. Looking forward to seeing how it comes out, and what (if anything happens to the tank, the sudden introduction of the word "Dude!" etc.
There will probably be more spoilers in comments if any.