I liked it overall. Part 1 (The Impossible Astronaut) works better basically for the lakeside picnic scene, and the visual grandeur it lent the episode (Utah's a lovely place, wish I could visit someday). Also liked the succeeding scene at the diner, which answers two questions ("1. When you take an irreparable step just seven minutes into a season premiere, how do you carry on for the rest of the episode?" and "2. Who does the Doctor trust most of all?"), and the scene at the TARDIS immediately after ("A mysterious summons. What, and I go, just like that?"). One, two, three: Moffat introduces the theme of mortality (every memorable legend from Robin Hood to King Arthur has to have a memorable end, and I feel Moffat has just mustered the effrontery to start preparing us for the Doctor's), shows us the reaction of the Doctor's friends to this theme (introducing a gigantic twist along the way) and, on top of that, shows us the all-too-human, all-too-understandable reaction of the gigantic twist to the twist ("Why should I trust you?").
I love it that Dr. Song is offended, even angry; I love it that she seems just as offended by his choice of No. 1 Most Trusted ("This is cold; even by your standards, this is cold..."). I love it that Rory has to act as hapless go-between to the Doctor and the women, and later, as patient hand-holder to an awestruck newcomer ("It's bigger on the inside than on the outside...").
The business of the girl on the phone, the mysterious spaceman, and the even more mysterious Silence feel smaller, less urgent by comparison (though I do like Stuart Milligan's improbably likable Richard Nixon, and the latest addition to the Doctor's circle of friends, Canton Everett Delaware III (Mark Shepard)). We have heard the chimes at midnight, so on and so forth; we know time is limited (by two hundred years, true, but still...).
By Part 2 (Day of the Moon), however, the strong start seems to be falling apart. The business about Canton chasing them down; the astronaut suit; the Silence's prosthetics being a tad sillier-looking than, say the Weeping Angels' (those floppy fingers)...it's one thing after another, helter-skelter, and we end up feeling a bit confused, bewildered, even disappointed. All a bit much, I think, so we rebel by withholding our total involvement in all this.
It's not a bad episode--by any other standard than Moffat's it's excellent, with its emphasis on the wonders of the Apollo program, its sharp but sweet moment of poignancy ("there's a first for everything, right?"), and its lift-us-off-the-couch final revelation ("I'm dying. But I can fix that. It's easy, really...").
But overall, compared to, say, the fishsticks-and-custard scene in the previous season premiere (or the Doctor facing down his real opponent at the end of that episode), this feels like a more scattered--I'm tempted to say scatterbrained--effort. Compare either season's high points to Moffat's singletons (The Empty Child; The Doctor Dances; The Girl in the Fireplace; Blink)--to my mind Moffat's best work in the series to date--and in my book at least neither pass muster. There was something to the way Moffat could hook us, make us laugh, make us cry (or as close to crying as we'd care to admit), delight us with endless twists and surprises in the space of forty minutes (or an hour and a half) that was well-nigh miraculous. He came within the neighborhood of touching those previous highs with his work this past two years (The Eleventh Hour; the season finale), but has yet to exceed them (I'm actually more impressed with the episode he wrote for Sherlock, his updated take on the legendary detective).
It'll do for now, I suppose, but I'm hoping Moffat settles down and makes use of all the puzzle pieces he lays out, and that what we're seeing is mostly beginner's blues. I expect--no, hope--to eat my words, and gladly.