Rewatched The Power of Three the other day, probably the first time I've seen it since it aired.
When I went through The God Complex again recently, I thought this episode would've been such a good ending to Amy and Rory's story. I actually liked The Angels Take Manhattan but Moffat really tortures himself into creating a scenario where they are separated from the Doctor forever and effectively dead as far as the show is concerned. Whereas the way The God Complex treats it, it feels like a completely natural way to say goodbye, with the Doctor being the one to give them up in a moment of pure brutal honesty.
But Chibnall, with The Power of Three, really justifies -- better than Moffat does imo -- in keeping Amy and Rory on past that point. Despite how rushed it is, I really like the depiction of the passage of time in Amy and Rory's lives, how they're becoming more comfortable with real life over TARDIS life and the latter beginning to feel like more of an intrusion or distraction than an escape. It allows for some nice character moments between both the two of them and Amy and the Doctor. I like that we're treated to glimpses of friends and jobs and life milestones that happen over several years in their lives that are just out-of-context fragments for the Doctor, because it reflects how he sporadically he drops into their lives and how increasingly disruptive that's becoming. Even if all the cube stuff is pretty superfluous, all the character bits in here I think are Chibnall's best writing for the show.
I also wish this angle had been seeded in Asylum of the Daleks, rather than Moffat going with that episode's bizarre sudden divorce angle, so that S7 Pt. 1 was built more around Amy and Rory simply drifting away from the Doctor and growing into their own lives outside of the TARDIS. As it is, it kind of feels like Moffat and Whithouse/Chibnall are writing Amy and Rory in somewhat different directions here. That Amy and Rory were briefly divorced has no real bearing on anything else that happens to them the rest of the season and that feels really off. Though it does get to one complaint I had about Moffat's writing during this era: the only thing he ever knew to do with Amy and Rory was to pull them apart so he had an excuse to get them back together.