Finally got to watch this over the weekend. It was an OK episode, if a bit reminiscent of previous stories. The Doctor himself remarks that he's run into more than a few "last surviving" groups of humans over the years.
I was especially reminded of "The Ark in Space" (hibernating humans) and "The Happiness Patrol" (the whole "Be happy or die!" scenario). I like the relationship between and Bill, and the development of the mystery of the Doctor's oath and of whoever's in the vault.
Overall; Pretty good stuff.
Q: "Where do the writers get their ideas?"
A: From old episodes of Doctor Who.
This one reminded me of "Robots of Death" because of the little yellow "mood discs" substituting for bicycle reflectors. (That, and y'know, the "robots of death.")
This episode (and the next two) work hard at Moffat's promise that this would be a "back to basics" series that could serve as a jumping on point for new viewers. A straightforward (almost cliched) very Doctor Who-y* plot, with a slow-but -steady unpacking of the DW basics for Bill.
I like this one OK. Really like Bill.
*I'm now contemplating a show called "Doctor Hooey."