(Short reviews: Empty Child/Doctor Dances: genuinely great. The Girl in the Fireplace: had its moments, but over all fairly mediocre and seriously flawed by Moffat's "the Doctor is in love with MY special fairy princess!" thing. Blink: Strong first three quarters sabotaged by forcing the characters to be total idiots at the end to push the plot along, not to mention the supposedly terrifyingly fast monsters becoming slow as molasses.)
Silence in the Library starts well; spooky setup, creepy messages, mysterious double world. Then the expedition arrives, and I shortly realized that yes, we had another of Moffat's special fairy princesses on hand. And just like in Girl in the Fireplace, the actual companion(s) are quickly quarantined into a subplot that has no real connection to, and more importantly no impact on, the progress of the main plot. So that Moffat can expound on just how wonderful and unique the princess is ("everyone loves her, including the Doctor! she can read the Doctor's mind!" "she knows the Doctor's true name, not like any of those *lesser* companions! she and the Doctor had a long romance across time!")
This is not to bash all one episode characters; I kept comparing her to Ada in The Impossible Planet/The Satan Pit, a character I _adored_. I loved that Ada was a cool strong character and her conversations with the Doctor were wonderful. But she wasn't a special fairy princess -- she was a strong, smart woman full of personality. And she wasn't used at Rose's expense; Rose's side of the plot was equally key to a successful outcome, since she helped get people to safety and had the coolness of mind to eject the demon-spirit back into the black hole, sabotaging its final escape.
In comparison, Donna basically swans around in cyberspace for half of the episodes. Nothing she does affects the success of the main plot; nothing she does even affects her own rescue. She doesn't even come to the solid conclusion on her own that she's trapped in an illusion; she in fact turns away from that information to cling to said illusion. Now, Catherine Tate does a yeoman job here, fighting to give the sequences emotional weight, but it doesn't make up for the featherweight in plot.
In fact, all the characters suffer in comparison to TIP/TSP, where a half dozen characters were each given their own individual personality and value. It's as if Moffat, having assigned them the roles of victims 1 through 4, didn't see any further need to spend time developing their characters -- hell, two of them didn't even get *any* characterization, making the sketchy "featherbrained" and "realistic in the face of death" pair veritable symphonies of depth in comparison.
The result is that I cared increasingly less as they got eaten. The first had the one real flash of brilliance in this pair of episodes -- the group standing around horrified as the woman's fading neural ghost pleaded against the dark. The second one at least was mildly creepy, but "ooooooh! mobile skeleton in a suit!" had less impact with every rendition, resulting in the final "he's been having a conversation with a skeleton! ooooooh!" one being a yawn.
And what the hell was the nonsense with the screwdriver at the end? The computer was perfectly capable of recording anyone in a suit, as demonstrated by the end. The exact same suit that Song was *already wearing*. So the frantic running around with the screwdriver was pointless.
And as a solution, it struck me as not particularly good, for either side. A bunch of reproductions of people stuck forever with each other in a computer. And a bunch of eternally starving Varada -- given there are still trillions of them after a hundred years, they apparently don't die off -- waiting for people to forget again and send an expedition.
It's possible that Moffat as producer will be slightly less annoying; he'll be able to make the his special fairy princesses the companion, instead of finding an excuse to put the actual companions in a box so that he can expound on how wonderful his characters are. And if they show up for more than an episode or two maybe they'll get some characterization beyond "they are super special and the Doctor loves them best!"
But mostly I'll be hoping he's smart and hires Paul Cornell to write more episodes.