Great episode! I don't remember that part with him in the jacket coming back in the original episode, I wonder if that was cut out of the TV edit. I think I like Part 1 more though, I kind of wish the gravity failing at the end felt more deliberate. Like the Doctor could have been also counting down over time and we think its related to Amy counting down, but the Doctor could have been counting down until the gravity fails so he knows when to tell everyone to hold on. Instead it kind of felt like he realized the gravity was failing as the convenient right moment, still a great episode with great setting, characters, dialogue etc.